Optical information recording medium, optical information recording apparatus, and method of recording test signal on the same

ABSTRACT

An optical information recording apparatus, an optical information recording method, and an optical information recording medium that enable information signals to be recorded precisely by determining recording conditions such as recording power, edge positions of recording pulses, and the like suitably before recording information signals. An edge test signal generation circuit supplies a test signal for optimizing edge positions of recording pulses. In order to suppress the variation in intervals between edges due to mark distortion caused by overwriting, test recording is carried out using this test signal in a plurality of sectors on the optical information recording medium with a test recording start point being shifted at random in each sector by a recording start point shifting circuit. A system control circuit calculates an average of intervals between edges in test signals reproduced from the plurality of sectors and determines the difference between the average and an original interval between edges in the test signal, thus determining a compensation volume for edge positions.

FIELD OF THE INVENTION

The present invention relates to an optical information recordingmedium, such as, for example, an optical disk, used for recording andreproducing information optically, an information recording method inwhich test signals are recorded before the recording of informationsignals to optimize recording conditions, and an informationrecording/reproducing apparatus.

BACKGROUND OF THE INVENTION

Recently, as media used for recording information optically, an opticaldisk, an optical card, an optical tape, and the like have been proposedand developed. Among them, the optical disk has been receiving attentionas a medium on which mass information can be recorded with high densityand from which the mass information can be reproduced.

One system of rewritable optical disks is a phase-change type opticaldisk. A recording film used in the phase-change type optical disk ischanged to either an amorphous state or a crystalline state depending ona heating condition by a laser beam and a cooling condition. There isreversibility between the amorphous state and the crystalline state. Theabove-mentioned amorphous state and the crystalline state are differentin optical constants (a refractive index and an extinction coefficient)of the recording film. In the phase-change type optical disk, the twostates are produced in the recording film selectively according toinformation signals. By using the optical change (the change intransmittance or reflectance) thus caused, the information signals arerecorded and reproduced.

In order to obtain the above-mentioned two states, the following methodis used in recording information signals. When a laser beam (with apower level P_(p)) focused by an optical head is irradiated onto arecording film of an optical disk in the form of pulse (which is called“a recording pulse”) to increase the temperature of the recording filmabove its melting point, a molten portion is cooled quickly after thepassage of the laser beam to form a recording mark in an amorphousstate. On the other hand, when a laser beam (with a power level P_(b),wherein P_(b)<P_(p)) is focused and irradiated with a power at a levelthat allows the temperature of the recording film to increase to thetemperature above that causing the recording film to change to acrystalline state but below its melting point, the irradiation part inthe recording film is changed to a crystalline state. This power levelP_(b) is called “an erase power”.

Thus, corresponding to a recording data signal, a recording patternincluding recording marks formed of amorphous areas and portions with nomark (called “spaces”) formed of crystalline areas is formed on trackson the optical disk. By utilizing the differences in opticalcharacteristics between the crystalline areas and the amorphous areas,information signals can be reproduced.

Recently, instead of a mark position recording (that also is called “PPMrecording”) system, a mark edge recording (that also is called “PWMrecording”) system has been increasingly used. In the mark positionrecording, information is given only to positions of recording marksthemselves. On the other hand, in the mark edge recording, informationis given to both edge positions at a leading edge and a rear edge ofeach recording mark, resulting in the advantage of improving recordinglinear density.

Further, as a method of facilitating rotation control of a spindle motorin a recording/reproducing apparatus while increasing recording capacityin an optical disk, a Z-CLV (Zoned Constant Linear Velocity) format hasbeen proposed. In an optical disk with the Z-CLV format, a recordingarea is divided into zones including a predetermined number of tracks,and the number of sectors around the disk is increased gradually from azone in the inner circumference toward that in the outer circumference.

In an apparatus used for recording information on and reproducinginformation from such a Z-CLV disk, information is recorded orreproduced by reducing the rotation speed of the disk gradually from theinner circumference toward the outer circumference (wherein the rotationspeed in each zone is constant) and allowing the linear velocity to besubstantially constant throughout all rounds on the disk.

The Z-CLV format is described, for example, as “an M-CLV (ModifiedConstant Linear Velocity) format” in “Optical Disk Technology”, page223, Radio Technique Co. Ltd., (1988).

Optical disks are exchangeable recording media and thereforerecording/reproducing apparatuses for optical disks are required torecord information on and reproduce information from a plurality ofdifferent optical disks stably. However, even in optical disksmanufactured under the same conditions, the optimum power level of alaser beam for recording and reproducing information may be differentdue to irregularity during the manufacture or aging. Further, because ofdirt on the substrate surface of an optical disk, the decrease intransmission efficiency in an optical system or the variation inoperation condition in a recording/reproducing apparatus, the power of alaser beam reaching a recording film of the optical disk may vary.

In addition, particularly in the mark edge recording system, thevariation in thermal characteristics of an optical disk affects theformation state of recording marks themselves and the degree of thethermal interference between the recording marks. Therefore, the optimumedge positions of recording pulses may be different in each opticaldisk.

An example of methods of recording and reproducing information signalsstably without being affected by such variation in optimum power levelof a laser beam or in optimum edge positions of recording pulses asdescribed above has been disclosed in JP 4-137224 A. In the exampledisclosed therein, after carrying out test recording with a specificdata pattern (which is called “a test signal”) prior to the recording ofinformation signals, the test signal recorded is reproduced and edgepositions of recording marks are determined by measuring the signalreproduced, thus controlling the edge positions of recording pulses tobe optimum.

As another example, JP 6-195713 A discloses a technique in which edgepositions of recording marks are determined and then at least oneselected from edge positions of recording pulses and recording power iscontrolled. In JP 9-63056 A, a method for determining an optimumrecording power based on the power dependency of a bit error rate hasbeen disclosed. Further, JP 7-129959 A discloses a method of controllingedge positions of recording pulses according to the length of therecording marks and the length of the spaces directly before and afterthe respective recording marks.

On the other hand, a method of increasing the number of times an opticaldisk can be rewritten has been proposed in JP 9-219022 A. In thismethod, by inverting the polarity (1 or 0) of a recording data signal atrandom, the concentration of damage at specific positions on a recordingfilm is avoided, thus suppressing the deterioration of the recordingfilm.

However, in the aforementioned conventional methods, since measuredvalues of edge positions of recording marks vary, errors in determiningedge positions of recording pulses may occur, which has been a problem.This problem will be explained with reference to FIGS. 11 to 14 asfollows.

FIGS. 11 to 14 show examples of mark distortion caused by the positionrelationship between recording marks that had been recorded previouslyand recording marks that have been overwritten. Each figure of FIGS. 11to 14 shows the state of a track on an optical disk before theoverwriting of recording marks in the upper section, a pattern of a testsignal (as a recording data signal) to be overwritten in the middlesection, and the state of the track after the overwriting of therecording marks in the lower section.

Conventionally, in many cases, a predetermined track is assigned as thetrack on which recording marks for test recording are to be recorded. Inthis case, recording marks are overwritten on the predetermined trackrepeatedly. Therefore, when a test signal (or an information signal) hadbeen recorded on the track on which test recording should be carriedout, the shapes of the recording marks that have been overwritten andthus recorded are distorted due to the influence of the recording marksthat had previously been recorded.

When using a phase-change type optical disk, amorphous areas (i.e. theareas where recording marks are present) and crystalline areas aredifferent in optical absorption property. Therefore, even when laserbeams with the same energy are irradiated, the temperature increase ratein a recording film of the optical disk is different in the amorphousareas and the crystalline areas. Thus, in the case of a disk designed sothat optical absorptance in the amorphous areas is higher than that inthe crystalline areas, recording marks overwritten tend to be increasedin size in the amorphous areas. As a result, edge positions of therecording marks shift in the direction in which the recording marksextend as shown with hatching in FIGS. 11 to 14, which is called “markdistortion”. When a disk is designed so that optical absorptance in theamorphous areas is lower than that in the crystalline areas, the resultopposite to the above may be obtained.

Therefore, the shapes of recording marks vary depending on the overlapcondition between recording marks recorded in test recording andrecording marks previously recorded. Consequently, the edge positions ofthe recording marks vary. When a signal that previously has beenrecorded on a track is the same as or similar to a test signaloverwritten, the overlap condition between the previous recording marksand the recording marks overwritten is always the same unless rotationalfluctuation of a disk is great. Therefore, depending on the phaserelation between a previous data pattern and a data pattern overwritten,measured values of the edge positions vary.

For example, as shown in the upper section in FIG. 11, when a recordingmark is overwritten on a track 111 on which a recording mark 113previously was present using a test signal with the pattern shown in themiddle section in FIG. 11, a recording mark 112 overwritten overlapswith the previous recording mark 113, thus causing mark distortion 114as shown in the lower section.

In the case where a leading edge position of a recording pulse of 3T(wherein T indicates a clock cycle of a recording data signal) isdetermined by measuring the interval x between the leading edge of therecording mark 112 and that of a recording mark 115, when the markdistortion 114 has occurred only at the end of the recording mark 112overwritten as shown in FIG. 11, the mark distortion 114 does not affectthe interval x. However, as shown in FIG. 12, when the leading edge ofthe recording mark 115 of a recording pulse of 3T to be overwrittenoverlaps with the previous recording mark 113, mark distortion 116occurs at the leading end of the recording mark 115. As a result, theinterval x measured is indicated by x−Δ₁.

Further, as shown in FIG. 13, when the leading end of the recording mark112 of a recording pulse of 10T overlaps with the previous recordingmark 113, mark distortion 114 occurs at the leading edge of therecording mark 112. As a result, the interval x measured is indicated byx+Δ₂.

As shown in FIG. 14, when both the leading edges of the recording mark115 of a recording pulse of 3T and of the recording mark 112 of arecording pulse of 10T overlap with the previous recording mark 113, theinterval x measured is indicated by x+Δ₂−Δ₁.

In the conventional methods, an optimum recording power cannot always beobtained after recording pulses have been controlled to have optimumedge positions, which has been a problem. This problem will be explainedwith reference to FIG. 15 as follows.

FIG. 15 shows the relationship between recording peak power P_(p) and abit error rate (or jitter) when a periodic signal of the shortest mark(for example, a recording mark formed by a recording pulse of 3T in thecase of 8-16 modulation, hereafter which is called “a 3T mark”) isrecorded while varying the recording pulse width.

When edge positions of recording pulses are adjusted by test recording,the length of the recording pulses (or a recording pulse train) varies.Therefore, the energy applied so that the recording pulses formrecording marks is affected by the adjustment of the edge positions.This influence becomes significant particularly when a short mark suchas the shortest mark is formed. As a result, the optimum recording poweralso varies.

For instance, when the length of a recording pulse for forming a 3T markof the shortest mark in the case of 8-16 modulation is shortened due tothe adjustment of edge positions, the energy used for forming the 3Tmark decreases. Therefore, the peak power dependency of a bit error rateshifts from g₁ to g₂ as shown in FIG. 15. Consequently, the optimumrecording power (which is generally determined by multiplying the powerP_(th1) or P_(th2) that allows the bit error rate to be a predeterminedthreshold value B_(th) by a certain value) becomes higher than thatbefore the adjustment of edge positions.

On the contrary to the above problem, in the conventional methods,optimum edge positions of recording pulses cannot always be obtainedafter the recording power has been adjusted, which also has been aproblem in some cases. This problem will be explained as follows.

When the recording power is adjusted by test recording, the energyapplied to a recording film of an optical disk by a laser beam varies.Therefore, even if recording pulses or recording pulse trains have thesame length, according to the change in recording power the length, i.e.edge positions, of recording marks formed on a track of the optical diskalso are changed. This influence is significant particularly when ashort mark is formed. As a result, the optimum edge positions ofrecording pulses that optimize edge positions of recording marks vary.For instance, when the recording power is increased based on testrecording, the leading edge of a 3T mark extends forward and its endedge extends backward. Consequently, the optimum edge positions of therecording pulse for recording the 3T mark cannot be obtained.

In the Z-CLV format, since an optical disk is rotated at a constantrotation speed in each zone, the linear velocity and linear density aredifferent depending on the radius within each zone. In other words, thelinear velocity and recording linear density decrease gradually towardthe outer circumference within each zone. Therefore, in the conventionalmethods, when test recording is carried out on an optical disk with theZ-CLV format, an optimum recording power or optimum edge positions ofrecording pulses cannot always be obtained throughout the whole areawithin each zone, which has been a problem.

Furthermore, in the method disclosed, for example, in JP 9-219022 A, thepolarity of a data pattern is inverted at random even when edgepositions of recording pulses are determined by test recording.Therefore, even when the same data pattern is recorded, the relationshipbetween a recording mark and a space (i.e. the relationship between theleading edge and the rear edge of a recording mark) may be reverseddepending on the polarity. In this case, the leading edge and the rearedge of a recording mark cannot be distinguished, which has been aproblem.

BRIEF DESCRIPTION OF THE INVENTION

In order to solve the aforementioned conventional problems, the presentinvention seeks to provide an optical information recording apparatus,an optical information recording method, and an optical informationrecording medium that enable information signals to be recordedprecisely by determining recording conditions such as recording power,edge positions of recording pulses, and the like suitably by testrecording.

In order to attain the above-mentioned object, a first opticalinformation recording apparatus of the present invention comprises: atest signal generation means that generates a test signal; a recordingmeans that converts the test signal and an information signal to arecording data signal, drives a light source based on the recording datasignal, and records the test signal and the information signal on anoptical information recording medium; a recording start point shiftingmeans that shifts a start point for test recording on the opticalinformation recording medium at random in each sector; a reproducingmeans that reproduces signals from the optical information recordingmedium; and a recording condition determination means that allows thetest signal generation means to supply the test signal to the recordingmeans, carries out the test recording in a plurality of sectors on theoptical information recording medium, and then determines edge positionsof pulses in the recording data signal based on an average of resultsobtained by reproducing the test signal from each of the plurality ofsectors by the reproducing means.

According to this configuration, the recording start point of the testsignal to be recorded in each of the plurality of sectors on the opticalinformation recording medium is shifted at random in each sector.Therefore, recording marks that previously have been recorded in an areaintended for the test recording and recording marks of the test signaloverwritten thereon overlap in random conditions in each sector. Thus,shifts in interval between edges in the test signal that are caused bymark distortion produced by the overwriting of the recording marks ofthe test signal on the recording marks that previously have beenrecorded are averaged. Consequently, variation caused by the phaserelation between the recording marks that previously have been recordedon the optical information recording medium and the recording marks ofthe test signal does not occur in values of the intervals between edgesthat are calculated from test signals reproduced. As a result, theinterval between edges of recording marks of the test signal can becalculated precisely, thus providing an optical information recordingapparatus that can record information signals precisely by optimizingedge positions in the recording data signal.

In order to attain the aforementioned object, a second opticalinformation recording apparatus of the present invention comprises: atest signal generation means that generates a test signal; a recordingmeans that converts the test signal and an information signal to arecording data signal, drives a light source based on the recording datasignal, and records the test signal and the information signal on anoptical information recording medium; a data pattern generation meansthat generates a data pattern having substantially no correlation withthe test signal; a reproducing means that reproduces signals from theoptical information recording medium; and a recording conditiondetermination means that allows the data pattern generation means tosupply the data pattern to the recording means to record the datapattern in an area for carrying out the test recording on the opticalinformation recording medium, then allows the test signal generationmeans to supply the test signal to the recording means to overwrite thetest signal in the area, and determines a proper value for edgepositions of recording pulses in the recording data signal based on aresult obtained by reproducing the test signal from the area by thereproducing means.

According to this configuration, before the test recording carried outon the optical information recording medium, the data pattern havingsubstantially no correlation with the test signal is recorded in thearea intended for the test recording and therefore recording marks ofthe test signal overwritten in the area and recording marks thatpreviously have been recorded overlap in random conditions. Thus, shiftsin interval between edges in the test signal that are caused by markdistortion produced by the overwriting of the recording marks of thetest signal on the recording marks that previously have been recordedare averaged. Consequently, variation caused by the phase relationbetween the recording marks that previously have been recorded on theoptical information recording medium and the recording marks of the testsignal does not occur in values of the intervals between edges that arecalculated from test signals reproduced. As a result, the intervalbetween edges of recording marks of the test signal can be calculatedprecisely, thus providing an optical information recording apparatusthat can record information signals precisely by optimizing edgepositions in the recording data signal.

It is preferable that the second optical information recording apparatusis further provided with a recording start point shifting means thatshifts a recording start point at random in each sector on the opticalinformation recording medium to shift the recording start point at leastof the test signal at random.

According to this configuration, shifts in interval between edges in thetest signal that are caused by the overwriting of the recording marks ofthe test signal on the recording marks that previously have beenrecorded can be further averaged, thus optimizing the edge positions inthe recording data signal further precisely.

In the second optical information recording apparatus, it is preferablethat the data pattern is a random pattern.

According to this configuration, since a random pattern is recorded inthe area intended for the test recording, shifts in interval betweenedges in the test signal that are caused by the overwriting of therecording marks of the test signal on the recording marks thatpreviously have been recorded can be further averaged, thus enabling anoptimum value for edge positions in the recording data signal to bedetermined further precisely.

In order to attain the aforementioned object, a third opticalinformation recording apparatus of the present invention comprises: atest signal generation means that generates a test signal; arecording/erasing means that is operated either in a recording mode inwhich the test signal and an information signal are converted to arecording data signal, a light source is driven based on the recordingdata signal, and the test signal and the information signal are recordedon an optical information recording medium or in an erasing mode inwhich light is irradiated onto the optical information recording mediumwith a predetermined erase power by driving the light source and thusinformation is erased from the optical information recording medium; areproducing means that reproduces signals from the optical informationrecording medium; and a recording condition determination means thatallows the recording/erasing means to operate in the erasing mode toerase information in an area for carrying out test recording on theoptical information recording medium, then allows the recording/erasingmeans to operate in the recording mode to record the test signalsupplied from the test signal generation means in the area, anddetermines a proper value for edge positions of recording pulses in therecording data signal based on a result obtained by reproducing the testsignal from the area by the reproducing means.

According to this configuration, the area intended for the testrecording on the optical information recording medium assumes aninitialized condition regardless of the states of recording marks thatpreviously have been recorded. Therefore, shifts in interval betweenedges in the test signal are not caused, thus optimizing the edgepositions in the recording data signal further precisely.

In order to attain the aforementioned object, a first opticalinformation recording method comprises steps of: (a) generating a testsignal; (b) shifting, at random in each sector, a start point of thetest recording of the test signal generated on an optical informationrecording medium; (c) converting the test signal shifted at random to arecording data signal, driving a light source based on the recordingdata signal, and carrying out the test recording in a plurality ofsectors on the optical information recording medium; (d) reproducing thetest signal recorded at the step (c) from each of the plurality ofsectors on the optical information recording medium; (e) calculating anaverage of results obtained by reproducing the test signal; and (f)determining edge positions of recording pulses in the recording datasignal based on the average calculated.

According to this method, the recording start point of the test signalrecorded in each of the plurality of sectors on the optical informationrecording medium is shifted at random in each sector. Therefore,recording marks that previously have been recorded in the area intendedfor the test recording and recording marks of the test signaloverwritten thereon overlap in random conditions in each sector. Thus,shifts in interval between edges in the test signal that are caused bymark distortion produced by the overwriting of the recording marks ofthe test signal on the recording marks that previously have beenrecorded are averaged. Consequently, variation caused by the phaserelation between the recording marks that previously have been recordedon the optical information recording medium and the recording marks ofthe test signal does not occur in values of the intervals between edgesthat are calculated from test signals reproduced. As a result, theinterval between edges of recording marks of the test signal can becalculated precisely, thus providing an optical information recordingapparatus that can record information signals precisely by optimizingedge positions in the recording data signal.

In order to attain the aforementioned object, a second opticalinformation recording method of the present information comprises stepsof: (a) generating a data pattern having substantially no correlationwith a test signal used for the above-mentioned test recording; (b)converting the data pattern generated to a recording data signal,driving a light source based on the recording data signal, and recordingthe data pattern in an area for carrying out the test recording on anoptical information recording medium; (c) generating the test signal;(d) converting the test signal generated to a recording data signal,driving the light source based on the recording data signal, andoverwriting the test signal in the area on the optical informationrecording medium; (e) reproducing the test signal overwritten at thestep (d) from the area on the optical information recording medium; and(f) determining a proper value for edge positions of recording pulses inthe recording data signal based on a result obtained by reproducing thetest signal.

According to this method, before the test recording carried out on theoptical information recording medium, the data pattern havingsubstantially no correlation with the test signal is recorded in thearea intended for the test recording and therefore recording marks ofthe test signal overwritten in the area and recording marks thatpreviously have been recorded overlap in random conditions. Thus, shiftsin interval between edges in the test signal that are caused by markdistortion produced by the overwriting of the recording marks of thetest signal on the recording marks that previously have been recordedare averaged. Consequently, variation caused by the phase relationbetween the recording marks that previously have been recorded on theoptical information recording medium and the recording marks of the testsignal does not occur in values of the intervals between edges that arecalculated from test signals reproduced. As a result, the intervalbetween edges of recording marks of the test signal can be calculatedprecisely, thus providing an optical information recording apparatusthat can record information signals precisely by optimizing edgepositions in the recording data signal.

It is preferable that the second optical information recording methodfurther comprises a step of shifting a recording start point at randomin each sector on the optical information recording medium and in thisstep the recording start point at least of the test signal is shifted atrandom.

According to this method, shifts in interval between edges in the testsignal that are caused by the overwriting of the recording marks of thetest signal on the recording marks that previously have been recordedcan be further averaged, thus optimizing the edge positions in therecording data signal further precisely.

In the second optical information recording method, it is preferablethat the data pattern is a random pattern.

According to this method, since a random pattern is recorded in the areaintended for the test recording, shifts in interval between edges in thetest signal that are caused by the overwriting of the recording marks ofthe test signal on the recording marks that previously have beenrecorded can be further averaged, thus enabling an optimum value foredge positions in the recording data signal to be determined furtherprecisely.

In order to attain the aforementioned object, a third opticalinformation recording method of the present information comprises stepsof: (a) erasing information in an area for carrying out theabove-mentioned test recording from an optical information recordingmedium by driving a light source to irradiate light onto the opticalinformation recording medium with a predetermined erase power; (b)generating a test signal; (c) converting the test signal generated to arecording data signal, driving the light source based on the recordingdata signal, and recording the test signal in the area for carrying outthe test recording on the optical information recording medium; (d)reproducing the test signal recorded at the step (c) from the area onthe optical information recording medium; and (e) determining a propervalue for edge positions of recording pulses in the recording datasignal based on a result obtained by reproducing the test signal.

According to this method, the area intended for the test recording onthe optical information recording medium assumes an initializedcondition regardless of the states of recording marks that previouslyhave been recorded. Therefore, shifts in interval between edges in thetest signal are not caused, thus optimizing the edge positions in therecording data signal further precisely.

In order to attain the aforementioned object, a fourth opticalinformation recording apparatus of the present invention comprises: atest signal generation means that generates an edge test signal and apower test signal; a recording means that converts the edge test signal,the power test signal, and an information signal to a recording datasignal, drives a light source based on the recording data signal, andrecords the edge test signal, the power test signal, and the informationsignal on an optical information recording medium; a recording pulseedge adjusting means that adjusts edge positions of recording pulses inthe recording data signal; a reproducing means that reproduces signalsfrom the optical information recording medium; a first recordingcondition determination means that allows the test signal generationmeans to supply the edge test signal to the recording means to recordthe edge test signal on the optical information recording medium anddetermines a set value for the edge positions of recording pulses forthe recording pulse edge adjusting means based on a result obtained byreproducing the edge test signal from the optical information recordingmedium by the reproducing means; and a second recording conditiondetermination means that allows the test signal generation means tosupply the power test signal to the recording means to record the powertest signal on the optical information recording medium and determines aset value of recording power of the light source for the recording meansbased on a result obtained by reproducing the power test signal from theoptical information recording medium by the reproducing means. In thefourth optical information recording apparatus, the first recordingcondition determination means determines a proper value for the edgepositions of recording pulses for the recording pulse edge adjustingmeans based on a result obtained by reproducing an edge test signalrecorded with a recording power whose set value is an initial value. Thesecond recording condition determination means determines a proper valueof the recording power of the light source for the recording means basedon a result obtained by reproducing the power test signal recorded withedge positions of recording pulses of which the set value determined bythe first recording condition determination means is the proper value.

According to this configuration, after the determination of the propervalue for the edge positions of recording pulses, test recording isfurther carried out with the recording pulses that have been set to theproper value to optimize the recording power, thus optimizing both theedge positions of recording pulses and the recording power. Therefore,information signals can be recorded precisely on the optical informationrecording medium.

It is preferable that the fourth optical information recording apparatusfurther comprises a recording start point shifting means that shifts arecording start point at random in each sector on the opticalinformation recording medium when the test recording of the edge testsignal is carried out.

According to this configuration, shifts in interval between edges in thetest signals that are caused by the overwriting of the recording marksof the test signals on recording marks that previously have beenrecorded in the area intended for the test recording on the opticalinformation recording medium can be averaged, thus optimizing the edgepositions in the recording data signal further precisely.

It is preferable that the fourth optical information recording apparatusfurther comprises a data pattern generation means that generates a datapattern having substantially no correlation with the edge test signaland the data pattern is recorded before the test recording of the edgetest signal by the recording means in an area where the edge test signalis to be recorded on the optical information recording medium.

According to this configuration, the correlation between the recordingmarks of the test signals overwritten in the area intended for the testrecording and recording marks that previously have been recorded isfurther decreased. Therefore, shifts in interval between edges in thetest signals can be averaged, thus optimizing the edge positions in therecording data signal further precisely.

In the fourth optical information recording apparatus, it is preferablethat the first recording condition determination means is provided witha means for comparing an interval between edges in the edge test signaland that in a reproduction signal obtained by reproducing the edge testsignal from the optical information recording medium to determine theproper value for the edge positions of recording pulses.

It is preferable that the fourth optical information recording apparatusfurther comprises a measurement means for measuring either a bit errorrate or jitter of the reproduction signal obtained by reproducing theedge test signal from the optical information recording medium and thefirst recording condition determination means determines an edgeposition of a recording pulse that allows a measurement result by themeasurement means to be the minimum as the proper value.

It is preferable that the fourth optical information recording apparatusfurther comprises a measurement means for measuring either a bit errorrate or jitter of a reproduction signal obtained by reproducing thepower test signal from the optical information recording medium and thesecond recording condition determination means determines the propervalue of the recording power based on a recording power value thatallows a measurement result by the measurement means to be apredetermined value or less.

In the fourth optical information recording apparatus, it is preferablethat the second recording condition determination means determines theinitial value of the recording power of the light source for therecording means based on a result obtained by reproducing the power testsignal recorded with edge positions of recording pulses of which the setvalue determined by the first recording condition determination means isa predetermined value.

According to this configuration, both the edge positions of recordingpulses and the recording power can be optimized further precisely, thusenabling information signals to be recorded on the optical informationrecording medium precisely.

Further, it is preferable that a measurement means for measuring eithera bit error rate or jitter of a reproduction signal obtained byreproducing the power test signal from the optical information recordingmedium is further provided and the second recording conditiondetermination means determines the proper value of the recording powerbased on a recording power value that allows a measurement result by themeasurement means to be a predetermined value or less and uses theproper value as the initial value of the recording power.

In order to attain the aforementioned object, a fourth opticalinformation recording method comprises steps of: (a) setting recordingpower of a light source to an initial value and recording an edge testsignal on an optical information recording medium; (b) determining aproper value for edge positions of recording pulses based on a resultobtained by reproducing the edge test signal recorded at the step (a)from the optical information recording medium; (c) setting the edgepositions of recording pulses to the proper value determined at the step(b) and recording a power test signal on the optical informationrecording medium; and (d) determining a proper value of the recordingpower based on a result obtained by reproducing the power test signalrecorded at the step (c) from the optical information recording medium.

In this method, after the determination of the proper value for the edgepositions of recording pulses, test recording is further carried outwith the recording pulses that have been set to the proper value, thusoptimizing the recording power. Consequently, both the edge positions ofrecording pulses and the recording power can be optimized, thus enablinginformation signals to be recorded on the optical information recordingmedium precisely.

In the fourth optical information recording method, it is preferablethat a recording start point on the optical information recording mediumis shifted at random in each sector at the step (a).

According to this method, shifts in interval between edges in the testsignal that are caused by the overwriting of the recording marks of thetest signal on recording marks that previously have been recorded in thearea intended for the test recording on the optical informationrecording medium can be averaged, thus optimizing the edge positions inthe recording data signal further precisely.

It is preferable that the fourth optical information recording methodcomprises, before the step (a), a step of recording a data patternhaving substantially no correlation with the edge test signal and thepower test signal in the area for carrying out the test recording on theoptical information recording medium.

According to this method, the correlation between the recording marks ofthe test signal overwritten in the area intended for the test recordingand recording marks that previously have been recorded is furtherdecreased. Therefore, shifts in interval between edges in the testsignal can be averaged, thus optimizing the edge positions in therecording data signal further precisely.

In the fourth optical information recording method, it is preferablethat the step (b) comprises a step of comparing an interval betweenedges in the edge test signal and that in a reproduction signal obtainedby reproducing the edge test signal from the optical informationrecording medium.

Alternatively, in the fourth optical information recording method, it ispreferable that the step (b) comprises a step of measuring either a biterror rate or jitter of the reproduction signal obtained by reproducingthe edge test signal from the optical information recording medium todetermine an edge position of a recording pulse that allows ameasurement result to be the minimum as the proper value.

In the fourth optical information recording method, it is preferablethat the step (d) comprises a step of measuring either a bit error rateor jitter of a reproduction signal obtained by reproducing the powertest signal from the optical information recording medium to determinethe proper value of the recording power based on a recording power valuethat allows a measurement result to be a predetermined value or less.

It is preferable that the fourth optical information recording methodfurther comprises, prior to the step (a), steps of: (e-1) recording thepower test signal on the optical information recording medium with edgepositions of recording pulses being set to a predetermined value; and(e-2) determining a proper value of the recording power based on aresult obtained by reproducing the power test signal recorded at thestep (e-1) from the optical information recording medium, and the propervalue of the recording power determined at the step (e-2) is used as theinitial value of the recording power at the step (a).

Thus, both the edge positions of recording pulses and the recordingpower can be optimized further precisely, thus enabling informationsignals to be recorded on the optical information recording mediumprecisely.

Further, it is preferable that the step (e-2) comprises a step ofmeasuring either a bit error rate or jitter of the reproduction signalobtained by reproducing the power test signal from the opticalinformation recording medium to determine the proper value of therecording power based on a recording power value that allows ameasurement result to be a predetermined value or less.

In order to attain the aforementioned object, a fifth opticalinformation recording apparatus of the present invention comprises: atest signal generation means that generates an edge test signal and apower test signal; a recording means that converts the edge test signal,the power test signal, and an information signal to a recording datasignal, drives a light source based on the recording data signal, andrecords the edge test signal, the power test signal, and the informationsignal on the optical information recording medium; a recording pulseedge adjusting means that adjusts edge positions of recording pulses inthe recording data signal; a reproducing means that reproduces signalsfrom the optical information recording medium; a first recordingcondition determination means that allows the test signal generationmeans to supply the edge test signal to the recording means to recordthe edge test signal on the optical information recording medium anddetermines a set value for the edge positions of recording pulses forthe recording pulse edge adjusting means based on a result obtained byreproducing the edge test signal from the optical information recordingmedium by the reproducing means; and a second recording conditiondetermination means that allows the test signal generation means tosupply the power test signal to the recording means to record the powertest signal on the optical information recording medium and determines aset value of recording power of the light source for the recording meansbased on a result obtained by reproducing the power test signal from theoptical information recording medium by the reproducing means. In thefifth optical information recording apparatus, the second recordingcondition determination means determines a proper value of the recordingpower of the light source for the recording means based on a resultobtained by reproducing the power test signal recorded with the edgepositions of recording pulses whose set value is an initial value. Thefirst recording condition determination means determines a proper valuefor the edge positions of recording pulses for the recording pulse edgeadjusting means based on a result obtained by reproducing the edge testsignal recorded with a recording power of which the set value determinedby the second recording condition determination means is theabove-mentioned proper value.

According to this configuration, after the determination of the propervalue of the recording power, test recording is further carried out withthe recording power set to the proper value, thus optimizing the edgepositions of recording pulses. Consequently, both the edge positions ofrecording pulses and the recording power can be optimized, thus enablinginformation signals to be recorded on the optical information recordingmedium precisely.

It is preferable that the fifth optical information recording apparatusfurther comprises a recording start point shifting means that shifts arecording start point at random in each sector on the opticalinformation recording medium when the test recording of the edge testsignal is carried out.

According to this configuration, shifts in interval between edges in thetest signals that are caused by the overwriting of the recording marksof the test signals on recording marks that previously have beenrecorded in the area intended for the test recording on the opticalinformation recording medium can be averaged, thus optimizing the edgepositions in the recording data signal further precisely.

It is preferable that the fifth optical information recording apparatusfurther comprises a data pattern generation means that generates a datapattern having substantially no correlation with the edge test signaland the data pattern is recorded before the test recording of the edgetest signal by the recording means in the area where the edge testsignal and the power test signal are to be recorded on the opticalinformation recording medium.

According to this configuration, the correlation between the recordingmarks of the test signals to be overwritten in the area intended for thetest recording and recording marks that previously have been recorded isfurther decreased. Therefore, shifts in interval between edges in thetest signals can be averaged, thus optimizing the edge positions in therecording data signal further precisely.

It is preferable that the fifth optical information recording apparatusfurther comprises a measurement means for measuring either a bit errorrate or jitter of a reproduction signal obtained by reproducing thepower test signal from the optical information recording medium and thesecond recording condition determination means determines the propervalue of the recording power based on a recording power value thatallows a measurement result by the measurement means to be apredetermined value or less.

In the fifth optical information recording apparatus, it is preferablethat the first recording condition determination means is provided witha means for comparing an interval between edges in the edge test signaland that in a reproduction signal obtained by reproducing the edge testsignal from the optical information recording medium to determine theproper value for the edge positions of recording pulses.

It is preferable that the fifth optical information recording apparatusfurther comprises a measurement means for measuring either a bit errorrate or jitter of the reproduction signal obtained by reproducing theedge test signal from the optical information recording medium and thefirst recording condition determination means determines an edgeposition of a recording pulse that allows a measurement result by themeasurement means to be the minimum as the proper value.

In the fifth optical information recording apparatus, it is preferablethat the first recording condition determination means determines theinitial value for the edge positions of recording pulses for therecording pulse edge adjusting means based on the result obtained byreproducing the edge test signal recorded with recording power of whichthe set value determined by the second recording condition determinationmeans is a predetermined value.

Thus, both the edge positions of recording pulses and the recordingpower can be optimized further precisely, thus enabling informationsignals to be recorded on the optical information recording mediumprecisely.

Further, it is preferred to further comprises a recording start pointshifting means that shifts a recording start point at random in eachsector on the optical information recording medium when the testrecording of the edge test signal is carried out.

In addition, it is preferable that a data pattern generation means thatgenerates a data pattern having substantially no correlation with theedge test signal is further provided and the data pattern is recordedbefore the test recording of the edge test signal by the recording meansin the area where the edge test signal is to be recorded on the opticalinformation recording medium.

It is preferable that the first recording condition determination meansis provided with a means for comparing an interval between edges in theedge test signal and that in the reproduction signal obtained byreproducing the edge test signal from the optical information recordingmedium to determine a proper value for the edge positions of recordingpulses.

It is preferable that a measurement means for measuring either a biterror rate or jitter of the reproduction signal obtained by reproducingthe edge test signal from the optical information recording medium isfurther provided, the first recording condition determination meansdetermines an edge position of a recording pulse that allows ameasurement result by the measurement means to be the minimum as aproper value, and the proper value for the edge positions of recordingpulses thus determined is used as the initial value.

In order to attain the aforementioned object, a fifth opticalinformation recording method of the present invention comprises stepsof: (a) setting edge positions of recording pulses to an initial valueand recording a power test signal on an optical information recordingmedium; (b) determining a proper value of recording power of a lightsource based on a result obtained by reproducing the power test signalrecorded at the step (a) from the optical information recording medium;(c) recording an edge test signal on the optical information recordingmedium based on the recording power determined at the step (b); and (d)determining a proper value for the edge positions of recording pulsesbased on a result obtained by reproducing the edge test signal recordedat the step (c) from the optical information recording medium.

In this method, after the determination of the proper value of therecording power, test recording is further carried out with therecording power set to the proper value, thus optimizing the edgepositions of recording pulses. Consequently, both the edge positions ofrecording pulses and the recording power can be optimized, thus enablinginformation signals to be recorded on the optical information recordingmedium precisely.

In the fifth optical information recording method, it is preferable thata recording start point on the optical information recording medium isshifted at random in each sector at the step (c).

According to this method, shifts in interval between edges in the testsignals that are caused by the overwriting of the recording marks of thetest signals on recording marks that previously have been recorded inthe area intended for the test recording on the optical informationrecording medium can be averaged, thus optimizing the edge positions inthe recording data signal further precisely.

It is preferable that the fifth optical information recording methodcomprises, before the step (c), a step of recording a data patternhaving substantially no correlation with the edge test signal in thearea for carrying out the test recording on the optical informationrecording medium.

According to this method, the correlation between the recording marks ofthe test signals to be overwritten in the area intended for the testrecording and recording marks that previously have been recorded isfurther decreased. Therefore, shifts in interval between edges in thetest signals can be averaged, thus optimizing the edge positions in therecording data signal further precisely.

In the fifth optical information recording method, it is preferable thatthe step (b) comprises a step of measuring either a bit error rate orjitter of a reproduction signal obtained by reproducing the power testsignal from the optical information recording medium and the propervalue of the recording power is determined based on a recording powervalue that allows the measurement result to be a predetermined value orless.

In the fifth optical information recording method, it is preferable thatthe step (d) comprises a step of comparing an interval between edges inthe edge test signal and that in a reproduction signal obtained byreproducing the edge test signal from the optical information recordingmedium.

In the fifth optical information recording method, it is preferable thatthe step (d) comprises a step of measuring either a bit error rate orjitter of the reproduction signal obtained by reproducing the edge testsignal from the optical information recording medium and an edgeposition of a recording pulse that allows a measurement result to be theminimum is determined as the proper value.

It is preferable that the fifth optical information recording methodfurther comprises, prior to the step (a), steps of: (e-1) recording theedge test signal on the optical information recording medium withrecording power being set to a predetermined value; and (e-2)determining a proper value for the edge positions of recording pulsesbased on a result obtained by reproducing the edge test signal recordedat the step (e-1) from the optical information recording medium, and theproper value for the edge positions of recording pulses determined atthe step (e-2) is used as the initial value for the edge positions ofrecording pulses at the step (a).

Thus, both the edge positions of recording pulses and the recordingpower can be optimized further precisely, thus enabling informationsignals to be recorded on the optical information recording mediumprecisely.

Further, it is preferable that a recording start point on the opticalinformation recording medium is shifted at random in each sector at thestep (e-1).

It is preferred to comprise, before the step (e-1), a step of recordinga data pattern having substantially no correlation with the edge testsignal in the area for carrying out the test recording on the opticalinformation recording medium.

It is preferable that the step (e-2) comprises a step of comparing aninterval between edges in the edge test signal and that in thereproduction signal obtained by reproducing the edge test signal fromthe optical information recording medium.

It is preferable that the step (e-2) comprises a step of measuringeither a bit error rate or jitter of the reproduction signal obtained byreproducing the edge test signal from the optical information recordingmedium and an edge position of a recording pulse that allows ameasurement result to be the minimum is determined as the proper value.

In order to attain the aforementioned object, a sixth opticalinformation recording apparatus of the present invention comprises: atest signal generation means that generates a test signal; a recordingmeans that converts the test signal and an information signal to arecording data signal, drives a light source based on the recording datasignal, and records the test signal and the information signal on anoptical information recording medium; a polarity inverting means thatinverts polarity of the recording data signal; a polarity inversioncontrol means that supplies only one of an inverted signal and anon-inverted signal of the recording data signal converted from the testsignal to the recording means when test recording is carried out and anyone selected at random in each sector from an inverted signal and anon-inverted signal of the recording data signal converted from theinformation signal to the recording means when the information signal isrecorded; a recording pulse edge adjusting means that adjusts edgepositions of recording pulses in the recording data signal; areproducing means that reproduces signals from the optical informationrecording medium; and a recording condition determination means thatdetermines a proper value for the edge positions of recording pulsesbased on a result obtained by reproducing the test signal from theoptical information recording medium by the reproducing means andsupplies the proper value to the recording pulse edge adjusting means.

According to this configuration, the number of times the opticalinformation recording medium can be rewritten increases and an opticalinformation recording apparatus that can record information signalsprecisely under the recording conditions optimized by the test recordingcan be provided.

It is preferable that the sixth optical information recording apparatusfurther comprises a recording start point shifting means that shifts arecording start point of the recording data signal at random in eachsector on the optical information recording medium.

According to this configuration, shifts in interval between edges in thetest signal that are caused by the overwriting of the recording marks ofthe test signal on recording marks that previously have been recorded inthe area intended for the test recording on the optical informationrecording medium can be averaged, thus optimizing the edge positions inthe recording data signal further precisely.

It is preferable that the sixth optical information recording apparatusfurther comprises a data pattern generation means that generates a datapattern having substantially no correlation with the test signal and thedata pattern is recorded on a track intended for the test recordingbefore the test recording is carried out.

According to this configuration, the recording marks of the test signaloverwritten in the area intended for the test recording and recordingmarks that previously have been recorded overlap in random conditions.Therefore, shifts in interval between edges in the test signal can beaveraged, thus optimizing the edge positions in the recording datasignal further precisely.

In the sixth optical information recording apparatus, it is preferablethat the recording condition determination means is provided with ameans for comparing an interval between edges in the test signal andthat in a reproduction signal obtained by reproducing the test signalfrom the optical information recording medium to determine the propervalue for the edge positions of recording pulses.

It is preferable that the sixth optical information recording apparatusfurther comprises a measurement means for measuring either a bit errorrate or jitter of the reproduction signal obtained by reproducing thetest signal from the optical information recording medium, and therecording condition determination means determines an edge position of arecording pulse that allows a measurement result by the measurementmeans to be a predetermined value or less as the proper value.

It is preferable that the sixth optical information recording apparatusis provided with a second test signal generation means that generates asecond test signal and a second recording condition determination means.The second recording condition determination means records any one of aninverted signal and a non-inverted signal of the second test signal onthe optical information recording medium with edge positions ofrecording pulses being set to the proper value by the recording pulseedge adjusting means, and the inverted signal and the non-invertedsignal are supplied from the second test signal generation means andhave been selected at random in each sector by the polarity inversioncontrol means. Then the second recording condition determination meansdetermines a proper value of the recording power of the light source forthe recording means based on a result obtained by reproducing the secondtest signal from the optical information recording medium by thereproducing means.

In test recording for determining the recording power, there is a highpossibility that the test recording is carried out with a higherrecording power than that used in test recording for determining theedge positions of recording pulses and in normal recording ofinformation signals. According to this configuration, in the testrecording for determining the recording power, the test recording iscarried out while inverting the polarity of the second test signal atrandom, thus preventing a recording film in the area intended for thetest recording on the optical information recording medium from beingdeteriorated.

Further, it is preferable that the sixth optical information recordingapparatus further comprises a measurement means for measuring either abit error rate or jitter of a reproduction signal obtained byreproducing the second test signal from the optical informationrecording medium, and the second recording condition determination meansdetermines the proper value of the recording power based on a recordingpower value that allows a measurement result by the measurement means tobe a predetermined value or less.

In order to attain the aforementioned object, a sixth opticalinformation recording method comprises steps of: (a) determiningrandomly whether the polarity of a first test signal is to be invertedand carrying out test recording of only one of an inverted signal and anon-inverted signal of the first test signal on a predetermined track ofan optical information recording medium; (b) determining a proper valuefor edge positions of recording pulses based on a result obtained byreproducing the first test signal that has been recorded at the step (a)from the optical information recording medium; and (c) selecting, atrandom in each sector, any one of an inverted signal and a non-invertedsignal of an information signal to be recorded on the opticalinformation recording medium and recording a selected signal on theoptical information recording medium with edge positions of recordingpulses being set to the proper value determined at the step (b).

According to this method, the number of times the optical informationrecording medium can be rewritten increases and information signals canbe recorded precisely under the recording conditions optimized by thetest recording.

In the sixth optical information recording method, it is preferable thata recording start point on the optical information recording medium isshifted at random in each sector at the step (a).

According to this method, shifts in interval between edges in the testsignal that are caused by the overwriting of the recording marks of thetest signal on recording marks that previously have been recorded in thearea intended for the test recording on the optical informationrecording medium can be averaged, thus optimizing the edge positions inthe recording data signal further precisely.

It is preferable that the sixth optical information recording methodcomprises, before the step (a), a step of recording a data patternhaving substantially no correlation with the first test signal on thepredetermined track.

According to this method, the recording marks of the test signaloverwritten in the area intended for the test recording and recordingmarks that previously have been recorded overlap in random conditions.Therefore, shifts in interval between edges in the test signal can beaveraged, thus optimizing the edge positions in the recording datasignal further precisely.

In the sixth optical information recording method, it is preferable thatthe step (b) comprises a step of comparing an interval between edges inthe first test signal and that in a reproduction signal obtained byreproducing the first test signal from the optical information recordingmedium.

In the sixth optical information recording method, it is preferable thatthe step (b) comprises a step of measuring either a bit error rate orjitter of the reproduction signal obtained by reproducing the first testsignal from the optical information recording medium and an edgeposition of a recording pulse that allows a measurement result to be theminimum is determined as the proper value.

It is preferable that the sixth optical information recording methodfurther comprises, between the steps (b) and (c), a step (b-1) ofselecting any one of an inverted signal and a non-inverted signal of asecond test signal at random in each sector and recording a selectedsignal on the optical information recording medium with edge positionsof recording pulses being set to the proper value determined at the step(b), and a step (b-2) of determining a proper value of the recordingpower based on a result obtained by reproducing the second test signalrecorded at the step (b-1) from the optical information recordingmedium.

In test recording for determining the recording power, there is a highpossibility that the test recording is carried out with a higherrecording power than that used in test recording for determining theedge positions of recording pulses and in normal recording ofinformation signals. According to this method, at the step (b-1) ofcarrying out the test recording for determining the recording power, thetest recording is carried out while inverting the polarity of the secondtest signal at random, thus preventing a recording film in the areaintended for the test recording on an optical information recordingmedium from being deteriorated.

Further, it is preferable that the step (b-2) comprises a step ofmeasuring either a bit error rate or jitter of a reproduction signalobtained by reproducing the second test signal from the opticalinformation recording medium and a proper value of the recording poweris determined based on a recording power value that allows a measurementresult to be a predetermined value or less.

In order to attain the aforementioned object, a seventh opticalinformation recording method of the present invention employs an opticalinformation recording medium with a Z-CLV format in which a plurality ofzones including a predetermined number of tracks are comprised in arecording area, the number of sectors around the disk recording mediumincreases gradually from an inner zone toward an outer zone, andrecording linear density decreases gradually from an inner circumferencetoward an outer circumference within one zone. In the seventh opticalinformation recording method, test recording is carried out on theoptical information recording medium before an information signal isrecorded on the optical information recording medium. The seventhoptical information recording method is characterized by comprising astep (a) of carrying out the test recording for recording a test signalwith substantially the same recording linear density as that of aninformation signal on an innermost track in each zone and a step (b) ofdetermining a proper value for either edge positions of recording pulsesor recording power based on a result obtained by reproducing the testsignal from the optical information recording medium.

According to this method, an excellent result as to jitter (or anexcellent bit error rate) can be obtained throughout from an innermostcircumference to an outermost circumference in each zone and thereforeinformation signals can be recorded precisely.

In the seventh optical information recording method, it is preferablethat the step (b) comprises a step of measuring either a bit error rateor jitter of a reproduction signal obtained by reproducing the testsignal from the optical information recording medium and the propervalue of the recording power is determined based on a recording powervalue that allows a measurement result to be a predetermined value orless.

In the seventh optical information recording method, it is preferablethat at the step (a), the track for the test recording is locatedsubstantially at an innermost circumference at least in one zone.

In the seventh optical information recording method, it is preferablethat at the step (a), the track for the test recording is located at theinner or outer side with respect to the recording area on the opticalinformation recording medium.

In order to attain the aforementioned object, a first opticalinformation recording medium of the present invention is an opticalinformation recording medium with a Z-CLV format in which a plurality ofzones including a predetermined number of tracks are comprised in arecording area, the number of sectors around the recording mediumincreases gradually from an inner zone toward an outer zone, andrecording linear density decreases gradually from an inner circumferencetoward an outer circumference within one zone. The first opticalinformation recording medium is characterized by having an area for testrecording substantially at an innermost circumference at least in one ofthe zones.

In order to attain the aforementioned object, a second opticalinformation recording medium of the present invention is an opticalinformation recording medium with a Z-CLV format in which a plurality ofzones including a predetermined number of tracks are comprised in arecording area, the number of sectors around the recording mediumincreases gradually from an inner zone toward an outer zone, andrecording linear density decreases gradually from an inner circumferencetoward an outer circumference within one zone. The second opticalinformation recording medium is characterized by having a test recordingarea at inner and outer sides with respect to the recording area and therecording linear density in the test recording area is substantially thesame as that of an information signal on an innermost track in each zonewithin the recording area.

In the first and second optical information recording media, it ispreferable that a recording film is formed of a phase-change material.

In the first to sixth optical information recording apparatuses, it ispreferable that test recording and recording conditions are set at leastat one time selected from the times: in adjusting the opticalinformation recording apparatus; on starting the optical informationrecording apparatus; after a lapse of a predetermined time from thestarting; in exchanging the optical information recording medium; when abit error rate of the optical information recording medium exceeds apredetermined value; and when environmental temperature changes.

According to this configuration, variable factors among opticalinformation recording apparatuses can be compensated by carrying outtest recording in adjusting the recording/reproducing apparatuses.Variable factors in an optical information recording apparatus itselfcan be compensated by carrying out test recording on starting theoptical information recording apparatus and after a lapse of apredetermined time from the starting. In addition, by carrying out testrecording in exchanging an optical information recording medium,variable factors between optical information recording media can becompensated. Further, by carrying out test recording when a bit errorrate of an optical information recording medium exceeds a predeterminedvalue, variable factors in the optical information recording mediumitself can be compensated. By carrying out test recording whenenvironmental temperature changes, variable factors caused by thetemperature dependency of an optical information recording apparatus andan optical information recording medium can be compensated.

The optical information recording apparatus that records information onan optical information recording medium by the first to seventh opticalinformation recording methods is characterized by setting test recordingand recording conditions at least at one time selected from the times:in adjusting the recording/reproducing apparatus; on starting therecording/reproducing apparatus; after a lapse of a predetermined timefrom the starting; in exchanging the optical information recordingmedium; when a bit error rate of the optical information recordingmedium exceeds a predetermined value; and when environmental temperaturechanges.

According to this configuration, variable factors among opticalinformation recording apparatuses can be compensated by carrying outtest recording in adjusting the recording/reproducing apparatuses.Variable factors in an optical information recording apparatus itselfcan be compensated by carrying out test recording on starting theoptical information recording apparatus and after a lapse of apredetermined time from the starting. In addition, by carrying out testrecording in exchanging an optical information recording medium,variable factors between optical information recording media can becompensated. Further, by carrying out test recording when a bit errorrate of an optical information recording medium exceeds a predeterminedvalue, variable factors in the optical information recording mediumitself can be compensated. By carrying out test recording whenenvironmental temperature changes, variable factors caused by thetemperature dependency of an optical information recording apparatus andan optical information recording medium can be compensated.

Moreover, in the first to sixth optical information recordingapparatuses, it is preferable that a recording film of the opticalinformation recording medium is formed of a phase-change material.

In the first to seventh optical information recording methods, it ispreferable that a recording film of the optical information recordingmedium is formed of a phase-change material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the configuration ofrecording/reproducing apparatuses according to first and sixthembodiments of the present invention.

FIG. 2 is a flowchart explaining the operation of therecording/reproducing apparatus according to the first embodiment.

FIG. 3 is a block diagram showing the configuration of arecording/reproducing apparatus according to a second embodiment of thepresent invention.

FIG. 4 is a flowchart explaining the operation of therecording/reproducing apparatus according to the second embodiment.

FIG. 5 is a block diagram showing the configuration ofrecording/reproducing apparatuses according to third and fourthembodiments of the present invention.

FIG. 6 is a flowchart explaining the operation of therecording/reproducing apparatus according to the third embodiment.

FIG. 7 is a flowchart explaining the operation of therecording/reproducing apparatus according to the fourth embodiment ofthe present invention.

FIG. 8 is a block diagram showing the configuration of arecording/reproducing apparatus according to a fifth embodiment of thepresent invention.

FIG. 9 is a flowchart explaining the operation of therecording/reproducing apparatus according to the fifth embodiment.

FIG. 10 is a flowchart explaining the operation of arecording/reproducing apparatus according to a sixth embodiment of thepresent invention.

FIG. 11 is an explanatory view showing an example of a state of a trackbefore test recording, a test signal for the test recording, and a stateof the track after the test recording based on the test signal in aconventional optical disk.

FIG. 12 is an explanatory view showing another example of a state of atrack before test recording, a test signal for the test recording, and astate of the track after the test recording based on the test signal ina conventional optical disk.

FIG. 13 is an explanatory view showing a further example of a state of atrack before test recording, a test signal for the test recording, and astate of the track after the test recording based on the test signal ina conventional optical disk.

FIG. 14 is an explanatory view showing yet another example of a state ofa track before test recording, a test signal for the test recording, anda state of the track after the test recording based on the test signalin a conventional optical disk.

FIG. 15 is a graph showing the relationship between a recording peakpower P_(p) and a bit error rate when a periodic signal of a shortestmark is recorded while varying a recording pulse width in a conventionaloptical disk.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be explained with reference tothe drawings as follows.

First Embodiment

FIG. 1 is a block diagram showing the schematic configuration of arecording/reproducing apparatus (an optical information recordingapparatus) of a first embodiment according to the present invention.

The recording/reproducing apparatus records and reproduces informationusing an optical disk 1. The apparatus is provided with a spindle motor10 for rotating the optical disk 1 and an optical head 9 for focusing alaser beam at a desired spot on the optical disk 1 by using a laser beamsource (not shown in the figure). The operation of the wholerecording/reproducing apparatus is controlled by a system controlcircuit 2 (a recording condition determination means). It is preferredto use a phase-change type disk with a recording film made of aphase-change material as the optical disk 1.

In order to record information on the optical disk 1, therecording/reproducing apparatus is provided with a recording start pointshifting circuit 3 (a recording start point shifting means) for shiftinga recording start point at random in each sector and an edge test signalgeneration circuit 4 (a test signal generation means) for generating atest signal for determining edge positions of recording pulses.

As a recording means, the recording/reproducing apparatus comprises: amodulation circuit 5 that generates a recording data signal binarizedaccording to an information signal to be recorded; a recording signalgeneration circuit 6 that generates recording pulses for driving a laseraccording to the recording data signal; and a recording pulse edgeadjusting circuit 7 that adjusts edge positions of the recording pulsesoutput from the recording signal generation circuit 6. Further, a laserdrive circuit 8 is provided for modulating a current for driving thelaser beam source inside the optical head 9 according to recordingpulses output from the recording pulse edge adjusting circuit 7.

In addition, as reproducing means for reproducing information from theoptical disk 1, the recording/reproducing apparatus comprises: areproduction signal processing circuit 11 that carries out waveformprocess of a reproduction signal based on the light reflected from theoptical disk 1; an edge timing detecting circuit 12 that detects timingsof edges in the reproduction signal; and a demodulation circuit 13 forobtaining reproduction information.

The operation of the recording/reproducing apparatus according to thepresent embodiment will be explained with reference to the flowchartshown in FIG. 2 as follows.

In test recording, first the optical head 9 seeks a predetermined trackon the optical disk 1 (Step 1, hereafter abbreviated such as “S1”) andthe system control circuit 2 determines a set value of recording powerin the laser drive circuit 8 (S2). Then, the edge test signal generationcircuit 4 generates a test signal and sends it out to the recordingsignal generation circuit 6 as a recording data signal (S3).

The recording signal generation circuit 6 detects how many channel clockperiods T correspond to an inversion interval (that is, the interval atwhich inversion takes place) in the recording data signal. Then thecircuit 6 generates a predetermined number of recording pulses withpredetermined widths in predetermined timings according to the lengthsof recording marks.

In this case, the recording start point shifting circuit 3 shifts thestart position of a recording gate signal at random in each sector andsends it out to the recording signal generation circuit 6. The recordinggate signal is a digital signal of “1” or “0”. Only when information isrecorded on the optical disk 1, the digital signal is “1”. In the caseother than that, the digital signal is “0”. However, conversely thedigital signal may be “0” when information is recorded, and in the caseother than that it may be “1”.

By the shift of the start position of the recording gate signal atrandom in this way, the recording start point of a series of recordingdata signal to be recorded in a sector on the optical disk 1 shifts atrandom in each sector (S4). Then, the recording pulse edge adjustingcircuit 7 inputs recording pulses to the laser drive circuit 8 fordriving the laser beam source.

The laser drive circuit 8 modulates a current for driving the laser beamsource according to the recording pulses, thus carrying out therecording in the intended sector (S5). The above-mentioned recordingoperations from S3 to S5 are repeated until the recording is completedin the predetermined number of sectors (Yes at S6).

As a result, even if test signals with the same pattern are overwrittenon the same track, the phase relationship between new recording marksand old recording marks varies at random in each sector. Therefore, markdistortions under various states shown in FIGS. 11 to 14 are presentwith equal probability.

After the recording of test signal, the optical head 9 reproduces thetest signal from the sector (S7) and the reproduction signal processingcircuit 11 equalizes and binarizes a signal reproduced. Then, the edgetiming detecting circuit 12 slices the reproduction signal binarized anddetects an inversion interval in the signal (S8), thus measuring aninterval between edges of recording marks. The interval between edgesthus measured is stored in a memory (not shown in the figures) in thesystem control circuit 2 (S9). The above-mentioned processes from S7 toS9 are repeated for all the sectors in which the test recording has beencarried out (until obtaining Yes at S10).

After that, the system control circuit 2 calculates the average ofmeasured values of intervals between edges that have been stored in thememory (S11). As described above, since the test signal has beenrecorded while shifting the recording start point of the test signal atrandom in each sector at S4, the shifts in interval between edges due tothe influence of various kinds of mark distortions (i.e. the influenceof Δ₁ and Δ₂ in FIGS. 11 to 14) as shown in FIGS. 11 to 14 are averaged.Therefore, in the average value of the intervals between edgescalculated at S11, variation caused by the phase relationship with aprevious data pattern does not occur. As a result, it is possible todetermine an ideal interval between edges in the same state as that whenan actual information signal is overwritten.

As a next step, the difference between the interval between edgescalculated from the reproduction signal obtained by reproducing a resultof the test recording and that in the test signal (for example, in thecase of the test signals shown in FIGS. 11 to 14, the difference between15T and the time corresponding to the interval between edges calculated)is determined (S12). Then, an edge position of a recording pulse (forexample, the leading edge of a recording pulse for recording a 3T markin the examples as shown in FIGS. 11 to 14) is determined to be theposition compensated for the above-mentioned difference (S13). The edgecompensation volume is set in the recording pulse edge adjusting circuit7 (S14), thus completing the test recording. After that, wheninformation signals are recorded actually, the recording is carried outaccording to the edge position of the recording pulse set in the circuit7. Consequently, recording marks can be formed having ideal edgepositions.

As described above, in the present embodiment, the recording start pointof the test signal is shifted at random in each sector and testrecording is carried out in a plurality of sectors. The average value ofintervals between edges of recording marks obtained from thereproduction signals is determined, and thus the test recording fordetermining edge positions of recording marks precisely without causingvariation can be carried out. As a result, information signals can berecorded further precisely.

Second Embodiment

FIG. 3 is a block diagram showing the schematic configuration of arecording/reproducing apparatus in a second embodiment of the presentinvention.

The recording/reproducing apparatus records and reproduces informationusing an optical disk 1. The apparatus is provided with a spindle motor10 for rotating the optical disk 1 and an optical head 9 for focusing alaser beam at a desired spot on the optical disk 1 by using a laser beamsource (not shown in the figure). The operation of the wholerecording/reproducing apparatus is controlled by a system controlcircuit 22.

As recording means (or recording/erasing means), therecording/reproducing apparatus comprises: an edge test signalgeneration circuit 4 that generates a test signal for determining edgepositions of recording pulses; a modulation circuit 5 that generates arecording data signal binarized according to an information signal to berecorded; a recording signal generation circuit 6 that generatesrecording pulses for driving a laser according to the recording datasignal; and a recording pulse edge adjusting circuit 7 that adjusts edgepositions of the recording pulses output from the recording signalgeneration circuit 6. Further, a laser drive circuit 8 is provided formodulating a current for driving a laser beam source in the optical head9 according to recording pulses output from the recording pulse edgeadjusting circuit 7.

In order to reproduce information from the optical disk 1, theabove-mentioned recording/reproducing apparatus also comprises: areproduction signal processing circuit 11 that carries out waveformprocess of a reproduction signal based on light reflected from theoptical disk 1; an edge timing detecting circuit 12 that detects timingsof edges in the reproduction signal; and a demodulation circuit 13 forobtaining reproduction information.

The recording/reproducing apparatus of the present embodiment isprovided with a data pattern generation circuit 21 instead of therecording start point shifting circuit 3 in the first embodiment. Thecircuit 21 generates a data pattern to be recorded before the recordingof a test signal on a track on which the test signal is to be recorded.As the data pattern, data having substantially no correlation with thetest signal is used.

Then, the operation of the recording/reproducing apparatus of thepresent embodiment controlled by the system control circuit 22 will beexplained using the flowchart shown in FIG. 4 as follows.

In test recording, first the optical head 9 seeks a predetermined trackon the optical disk 1 (S21) and the system control circuit 22 determinesa set value of recording power in the laser drive circuit 8 (S22). Then,the data pattern generation circuit 21 generates a data pattern havingsubstantially no correlation with the pattern of a test signal and sendsit out to the recording signal generation circuit 6 as a recording datasignal (S23). The recording data signal is converted to recording pulsesin the recording signal generation circuit 6 and a current for drivingthe laser is modulated in the laser drive circuit 8. Thus, the recordingdata signal is recorded in the sector in which the test recording is tobe carried out later (S24).

After that, a test signal is sent out from the edge test signalgeneration circuit 4 to the recording signal generation circuit 6 as arecording data signal (S25). The recording data signal is converted torecording pulses in the recording signal generation circuit 6 in thesame way and a current for driving the laser is modulated in the laserdrive circuit 8. Then, the recording data signal is overwritten in thesector in which the data pattern sent out from the data patterngeneration circuit 21 has been recorded at S24 (S26).

In this case, the data pattern that has been recorded at S24 before theoverwriting at S26 has substantially no correlation with the pattern ofthe test signal. Therefore, the recording marks formed based on the testsignal and previous recording marks overlap in random conditions. Thus,various kinds of mark distortions shown in FIGS. 11 to 14 are present atequal probabilities.

After the recording of the test signal, the optical head 9 reproducesthe signal in the sector in which overwriting has been carried out atS26 (S27) and the reproduction signal processing circuit 11 equalizesand binarizes a signal reproduced. Then, the edge timing detectingcircuit 12 slices the binarized signal and detects the inversioninterval in the signal (S28), thus measuring an interval between edgesof the recording marks. The interval between edges thus measured isstored in a memory in the system control circuit 22 (S29).

Then, the system control circuit 22 calculates the average of measuredvalues of intervals between edges (S30). As described above, since thedata pattern that has been recorded before the overwriting hassubstantially no correlation with the pattern of the test signal, theshifts in interval between edges due to the influence of various kindsof mark distortions (i.e. the influence of Δ₁ and Δ₂ in FIGS. 11 to 14)shown in FIGS. 11 to 14 are averaged. Therefore, in the value of theinterval calculated, the variation caused by the phase relationship withthe previous data pattern does not occur. As a result, it is possible todetermine a precise interval between edges of the recording marks.

As a next step, the difference between the interval calculated from thereproduction signal of the test signal that has been recorded in thetest recording and an original interval between edges of the test signal(for example, in the case of the test signals shown in FIGS. 11 to 14,the difference between 15T and the time corresponding to the intervalbetween edges calculated) is determined (S31). Then, an edge position ofa recording pulse (for example, the leading edge of the recording pulsefor recording a 3T mark in the examples as shown in FIGS. 11 to 14) isdetermined to be the position compensated for the above-mentioneddifference (S32). The edge compensation volume is set in the recordingpulse edge adjusting circuit 7 (S33), thus completing the testrecording. After that, when information signals are recorded actually,the information signals are recorded by applying the edge position ofthe recording pulse set in the circuit 7. Consequently, recording markscan be formed with ideal edge positions.

As described above, in the present embodiment, before the test recordingthe data pattern having substantially no correlation with the pattern ofthe test signal is recorded on a track on which the test signal is to berecorded. This permits the test recording for determining edge positionsof recording marks precisely without causing variation. As a result,information signals can be recorded further precisely.

In the present embodiment, when further using the configuration andmethod for recording and reproducing a test signal in a plurality ofsectors by providing the recording start point shifting circuit 3 thatshifts the recording start point at random as described in the firstembodiment, the correlation between the data pattern before the testrecording and the data pattern of the test signal is further decreased.Therefore, this is further preferable in that edge positions ofrecording pulses can be determined more precisely.

In the present embodiment, the data pattern to be recorded before therecording of the test signal was defined as a pattern havingsubstantially no correlation with that of the test signal. However, arandom pattern may be used as the data pattern. In this case, whenrandom recording information is given to the system control circuit 22beforehand and the recording information is modulated in the modulationcircuit 5, the data pattern generation circuit 21 can be omitted, whichis further preferable in that the configuration of therecording/reproducing apparatus can be simplified. Alternatively, whenrandom recording information is sent to the system control circuit 22from an external unit (for example, a computer) connected to therecording/reproducing apparatus and the recording information ismodulated in the modulation circuit 5, the same effect can be obtained.

The data pattern to be recorded before the recording of the test signalthat has substantially no correlation with that of the test signal maybe a data pattern of another test signal with a different pattern cycle.Similarly in this case, the data pattern generation circuit 21 can beomitted and thus the configuration of the recording/reproducingapparatus is simplified, which is further preferable.

Instead of the recording of the data pattern to be recorded before therecording of the test signal that has substantially no correlation withthat of the test signal, all the signals that have been recorded on atrack on which the test signal is to be recorded may be erased by theirradiation of a laser beam onto the optical disk 1 with a constantlevel of erase power (P_(b)). When the optical disk 1 is a phase-changetype optical disk, a region of a recording film irradiated continuouslywith the laser beam having the erase power P_(b) turns into acrystalline condition, thus erasing information that has been recorded.Similarly in this case, the data pattern generation circuit 21 can beomitted, which is further preferable in that the recording/reproducingapparatus can be simplified.

Third Embodiment

FIG. 5 is a block diagram showing the schematic configuration of arecording/reproducing apparatus in a third embodiment of the presentinvention.

The recording/reproducing apparatus records and reproduces informationusing an optical disk 1. The apparatus is provided with a spindle motor10 for rotating the optical disk 1 and an optical head 9 for focusing alaser beam at a desired spot on the optical disk 1 by using a laser beamsource (not shown in the figure). The operation of the wholerecording/reproducing apparatus is controlled by a system controlcircuit 32.

The recording/reproducing apparatus comprises: an edge test signalgeneration circuit 4 that generates a test signal for determining edgepositions of recording pulses (an edge test signal); a modulationcircuit 5 that generates a binarized recording data signal according toan information signal to be recorded; a recording signal generationcircuit 6 that generates recording pulses for driving a laser accordingto the recording data signal; and a recording pulse edge adjustingcircuit 7 that adjusts edge positions of the recording pulses outputfrom the recording signal generation circuit 6. Further, a laser drivecircuit 8 is provided for modulating a current for driving a laser beamsource in the optical head 9 according to recording pulses output fromthe recording pulse edge adjusting circuit 7.

In order to reproduce information from the optical disk 1, theabove-mentioned recording/reproducing apparatus also comprises: areproduction signal processing circuit 11 that carries out waveformprocess of a reproduction signal based on light reflected from theoptical disk 1; an edge timing detecting circuit 12 that detects timingsof edges in the reproduction signal; and a demodulation circuit 13 forobtaining reproduction information.

The configuration described above is substantially the same as thatshown in FIG. 1 in the first embodiment. The recording/reproducingapparatus of the present embodiment is different from that of the firstembodiment particularly in omitting the recording start point shiftingcircuit 3 and comprising a bit error rate (abbreviated as “BER” in thefigure) measuring circuit 31 that determines recording power and a powertest signal generation circuit 33 that generates a test signal fordetermining the recording power (a power test signal).

The operation of the recording/reproducing apparatus of the presentembodiment controlled by the system control circuit 32 will be explainedusing the flowchart shown in FIG. 6 as follows.

In test recording, first the optical head 9 seeks a predetermined trackon the optical disk 1 (S41) and a set value of recording power in thelaser drive circuit 8 is set to an initial value by the system controlcircuit 32 (S42). Then, a test signal for determining edge positions ofrecording pulses (an edge test signal) is sent out from the edge testsignal generation circuit 4 to the recording signal generation circuit 6as a recording data signal (S43). The recording signal generationcircuit 6 converts the recording data signal to recording pulses and thelaser drive circuit 8 modulates a current for driving the laser based onthe recording pulses, thus carrying out the recording in a sectorintended for the test recording (S44).

After the recording of the test signal, the test signal in the sector inwhich the recording has been carried out at S44 is reproduced by theoptical head 9 (S45) and the reproduction signal processing circuit 11equalizes and binarizes a reproduction signal. Then, the edge timingdetecting circuit 12 slices the binarized signal and detects aninversion interval in the signal (S46), thus measuring the intervalbetween edges of recording marks. The measured value is stored in amemory in the system control circuit 32 (S47).

After that, the system control circuit 32 (a first recording conditiondetermination means) calculates the average of the measured values ofintervals between edges (S48). Then, the difference between the intervalbetween edges calculated from the reproduction signal of the test signalthat has been recorded in the test recording and an original intervalbetween edges of the test signal (for example, in the case of the testsignals shown in FIGS. 11 to 14, the difference between 15T and the timecorresponding to the interval between edges calculated) is determined(S49: a comparison means). Then, an edge position of a recording pulse(for example, the leading edge of a recording pulse for recording a 3Tmark in examples as shown in FIGS. 11 to 14) is determined to be theposition compensated for the above-mentioned difference (S50). The edgecompensation volume is set in the recording pulse edge adjusting circuit7 (S51).

As a next step, the recording power is set to be the minimum within apower adjustable range (S52) and a power test signal generation circuit33 sends out a test signal for determining power (a power test signal)to the recording signal generation circuit 6 (S53). Then, based on therecording pulses generated from the test signal, the test signal isrecorded in the sector intended for the test recording (S54). Afterthat, the test signal recorded is reproduced (S55) and then isequalized, binarized, and the like in the reproduction signal processingcircuit 11.

The bit error rate measuring circuit (a measuring means) 31 measures abit error rate by comparing the pattern of the test signal and the datapattern reproduced (S56) and stores the measured value in the systemcontrol circuit 32. Until the recording power reaches the maximum withinthe adjustable range (Yes at S57), the recording power is increasedgradually (S58) and the above-mentioned steps from S53 to S56 arerepeated.

Then, the system control circuit (a second recording conditiondetermination means) 32 refers to the measured values stored in thememory and calculates the recording power value that allows the biterror rate to be a certain threshold (B_(th) in FIG. 15) (S59). Based onthe value, by carrying out processes of, for example, multiplying thevalue by a certain coefficient and the like, a proper value of therecording power is determined (S60) and the recording power is set tothe proper value in the laser drive circuit 8 (S61), thus completing thetest recording. According to this method, even when pulse width ischanged by the adjustment of edge positions of recording pulses, aninformation signal can be recorded with an optimum recording power.

As described above, in the present embodiment, after the test recordingfor determining an optimum value for edge positions of recording pulses,the test recording for determining an optimum value of the recordingpower is carried out with the edge positions of recording pulses beingset to the above-mentioned optimum value. Therefore, even when pulsewidth is changed by the adjustment of edge positions of recordingpulses, the recording power can be optimized. Consequently, aninformation signal can be recorded with the optimum edge positions andrecording power, thus obtaining an excellent effect in that theinformation signal can be recorded further precisely.

In the present embodiment, the recording power when the edge positionsare determined was set to a predetermined value at S42. However, when astep of carrying out the test recording for determining the recordingpower value is added before S42, the optimum edge positions of recordingpulses and the optimum recording power can be determined furtherprecisely, which is more preferable.

Moreover, when the configuration and method as described in the firstembodiment in which the recording start point shifting circuit 3 isprovided, the recording start point is shifted at random and a testsignal is recorded and reproduced in a plurality of sectors to determinethe optimum edge positions of recording pulses also are usedadditionally in the present embodiment, the test recording fordetermining edge positions of recording marks precisely without causingvariation can be carried out, which is more preferable.

In addition, when the configuration and method as described in thesecond embodiment in which the data pattern generation circuit 21 isprovided and a data pattern having substantially no correlation with thepattern of a test signal is recorded beforehand on a track on which thetest signal for determining edge positions of recording pulses is to berecorded also are used additionally, the test recording for determiningedge positions of recording marks precisely without causing variationcan be carried out, which is more preferable.

Further, when the configuration and method as described later in a fifthembodiment in which a polarity inversion control circuit 53, a polarityinverting circuit 54, and a select circuit 55 are provided and randompolarity inversion of a recording data signal is inhibited only when thetest signal for determining edge positions of recording pulses isrecorded also are used additionally, the number of times the opticaldisk can be rewritten increases and information signals can be recordedprecisely, which is further preferable.

Fourth Embodiment

The configuration of the recording/reproducing apparatus in a fourthembodiment of the present invention is the same as that shown in FIG. 5in the third embodiment. However, the control by the system controlcircuit 32 is different.

The operation of the recording/reproducing apparatus according to thepresent embodiment that is controlled by the system control circuit 32will be explained using FIG. 5 and the flowchart in FIG. 7.

In test recording, first the optical head 9 seeks a predetermined trackon the optical disk 1 (S71) and the system control circuit 32 sets anedge position of a recording pulse in the recording pulse edge adjustingcircuit 7 to a predetermined position (S72).

Then, the recording power is set to the minimum within a poweradjustable range (S73) and a test signal for determining power (a powertest signal) is sent out from the power test signal generation circuit33 to the recording signal generation circuit 6 (S74), thus recordingthe test signal in a sector intended for the test recording (S75).

As a next step, the test signal recorded is reproduced (S76) and then isequalized, binarized, and the like in the reproduction signal processingcircuit 11. The bit error rate measuring circuit (a measuring means) 31measures a bit error rate by comparing the pattern of the test signaland a data pattern reproduced (S77) and stores the measured value in thesystem control circuit 32. Until the recording power reaches the maximumwithin the adjustable range (Yes at S78), the recording power isincreased gradually (S79) and the above-mentioned processes from S74 toS77 are repeated.

Then, based on measured values stored, the system control circuit (asecond recording condition determination means) 32 calculates the powerthat allows the bit error rate to be a certain threshold (B_(th) in FIG.15) (S80). Based on the power, the recording power is determined (S81)and then is set in the laser drive circuit 8 (S82).

As a next step, a test signal for determining edge positions ofrecording pulses (an edge test signal) is sent out from the edge testsignal generation circuit 4 to the recording signal generation circuit 6as a recording data signal (S83). The recording signal generationcircuit 6 converts the recording data signal to recording pulses. Thelaser drive circuit 8 modulates a current for driving the laser based onthe recording pulses from the recording signal generation circuit 6,thus recording the test signal in the sector intended for the testrecording (S84).

After the recording of the test signal, the test signal is reproducedwith the optical head 9 from the sector in which the test recording hasbeen carried out (S85). The reproduction signal processing circuit 11equalizes and binarizes a reproduction signal. Then, the edge timingdetecting circuit 12 slices the binarized signal and detects aninversion interval in the signal (S86), thus measuring an intervalbetween edges of recording marks. The measured value is stored in amemory in the system control circuit 32 (S87).

After that, the system control circuit (a first recording conditiondetermination means) 32 calculates the average of measured values ofintervals between edges stored in the memory (S88). Then, the differencebetween the interval between edges calculated from the reproductionsignal of the test signal that has been recorded in the test recordingand an original interval between edges in the test signal (for example,in the case of the test signals shown in FIGS. 11 to 14, the differencebetween 15T and the time corresponding to the interval between edgescalculated) is determined (S89: a comparison means). Then, an edgeposition of a recording pulse (for example, the leading edge of arecording pulse for recording a 3T mark in examples as shown in FIGS. 11to 14) is determined to be the position compensated for theabove-mentioned difference (S90). The edge compensation volume is set inthe recording pulse edge adjusting circuit 7 (S91), thus completing thetest recording. According to the present method, even when the recordingpower is adjusted, information signals can be recorded with optimum edgepositions of recording pulses.

As described above, in the present embodiment, after the test recordingfor determining a proper value of the recording power, the testrecording for determining edge positions of recording pulses is carriedout with the recording power being set to the above-mentioned propervalue. This enables information signals to be recorded with optimum edgepositions of recording pulses, even when irradiation energy of a laserbeam is changed due to the adjustment of the recording power. As aresult, an excellent effect in that information signals can be recordedfurther precisely can be obtained.

In the present embodiment, the edge position in determining therecording power was set to a predetermined value at S72. However, when astep of carrying out the test recording for determining the edgeposition is added before S72, optimum edge positions of recording pulsesand optimum recording power can be determined further precisely, whichis more preferable.

Moreover, when the configuration and method as described in the firstembodiment in which the recording start point shifting circuit 3 isprovided, the recording start point is shifted at random and a testsignal is recorded and reproduced in a plurality of sectors to determinethe optimum edge positions of recording pulses also are usedadditionally in the present embodiment, the test recording fordetermining edge positions of recording marks precisely without causingvariation can be carried out, which is more preferable.

In addition, when the configuration and method as described in thesecond embodiment in which the data pattern generation circuit 21 isprovided and a data pattern having substantially no correlation with thepattern of a test signal is recorded beforehand on a track on which thetest signal for determining edge positions of recording pulses is to berecorded also are used additionally, the test recording for determiningedge positions of recording marks precisely without causing variationcan be carried out, which is more preferable.

Further, when the configuration and method as described later in a fifthembodiment in which a polarity inversion control circuit 53, a polarityinverting circuit 54, and a select circuit 55 are provided and randompolarity inversion of a recording data signal is inhibited only when thetest signal for determining edge positions of recording pulses isrecorded also are used additionally, the number of times the opticaldisk can be rewritten increases and information signals can be recordedprecisely, which is further preferable.

When the test recording for determining the optimum recording power andthe optimum edge positions of recording pulses is carried out, theconfiguration and method to be used may be selected from those in thepresent embodiment and those in the aforementioned third embodimentaccording to the configuration, recording density, modulation system, orthe like of the optical disk on which the test recording is carried out.For example, in the case of an optical disk in which the change injitter or bit error rate is sensitive to the shift in edge positions,the present embodiment is preferred. On the other hand, in the case ofan optical disk in which the change in jitter or bit error rate issensitive to the change in recording power, the third embodiment ispreferred.

Generally, the configuration of the recording/reproducing apparatusrequired for the test recording for determining edge positions ofrecording marks is more complex than that required for the testrecording for determining recording power. Therefore, when the testrecording for determining edge positions is carried out using anexternal measuring instrument such as, for example, a time intervalanalyzer, for instance, in adjusting the recording/reproducing apparatus(before shipping) and after that only the test recording for determiningrecording power is carried out, the third embodiment is preferred inthat the configuration of the recording/reproducing apparatus can besimplified.

Fifth Embodiment

FIG. 8 is a block diagram showing the schematic configuration of arecording/reproducing apparatus in a fifth embodiment of the presentinvention.

This recording/reproducing apparatus records and reproduces informationusing an optical disk 1. The apparatus is provided with a spindle motor10 for rotating the optical disk 1 and an optical head 9 for focusing alaser beam at a desired spot on the optical disk 1 by using a laser beamsource (not shown in the figure). The operation of the wholerecording/reproducing apparatus is controlled by a system controlcircuit 52.

The recording/reproducing apparatus comprises: an edge test signalgeneration circuit 4 that generates a test signal for test recording; amodulation circuit 5 that generates a recording data signal binarizedaccording to an information signal to be recorded; a recording signalgeneration circuit 6 that generates recording pulses for driving a laseraccording to the recording data signal; and a recording pulse edgeadjusting circuit 7 that adjusts edge positions of the recording pulsesoutput from the recording signal generation circuit 6. Further, a laserdrive circuit 8 is provided for modulating a current for driving a laserbeam source (not shown in the figure) in the optical head 9 according torecording pulses output from the recording pulse edge adjusting circuit7.

In order to reproduce information from the optical disk 1, theabove-mentioned recording/reproducing apparatus also comprises: areproduction signal processing circuit 11 that carries out waveformprocess of a reproduction signal based on light reflected from theoptical disk 1; an edge timing detecting circuit 12 that detects timingsof edges in the reproduction signal; and a demodulation circuit 13 forobtaining reproduction information.

The above-mentioned recording/reproducing apparatus further comprises: apolarity inverting circuit 54 that inverts the polarity of a recordingdata signal; a select circuit 55 containing a switch that switches theoutput address of the signal sent out from the modulation circuit 5 orthe edge test signal generation circuit 4 to either the recording signalgeneration circuit 6 or the polarity inverting circuit 54; and apolarity inversion control circuit 53 that inhibits random polarityinversion and cancels the inhibition.

The operation of the recording/reproducing apparatus of the presentembodiment will be explained using the flowchart shown in FIG. 9 asfollows.

In test recording, first the polarity inversion control circuit 53controls the select circuit 55 so as to fix the output address of thesignals output from the select circuit 55 to the recording signalgeneration circuit 6, so that all the data from the edge test signalgeneration circuit 4 does not go through the polarity inverting circuit54 (S101). Thus, the polarity inversion in recording data signal isinhibited.

As a next step, the optical head 9 seeks a predetermined track on theoptical disk 1 (S102) and the system control circuit 52 sets therecording power in the laser drive circuit 8 to a predetermined value(S103). Then, the edge test signal generation circuit 4 sends out a testsignal to the select circuit 55 as a recording data signal (S104). Inthis case, since the output address of the select circuit 55 has beenswitched to the recording signal generation circuit 6 at S101, all thetest signals sent out from the edge test signal generation circuit 4 areinput to the recording signal generation circuit 6 without going throughthe polarity inverting circuit 54.

As in the aforementioned embodiments, the recording signal generationcircuit 6 converts the test signal input to recording pulses for drivingthe laser. The laser drive circuit 8 modulates a current for driving thelaser based on the recording pulses, thus recording the test signal inthe sector intended for the test recording (S105).

After the recording of the test signal, the test signal in the sector inwhich the test recording has been carried out is reproduced with theoptical head 9 (S106) and the reproduction signal processing circuit 11equalizes and binarizes a reproduction signal. Then, the edge timingdetecting circuit 12 slices the binarized signal and detects aninversion interval in the signal (S107). Based on the inversion intervaldetected, the system control circuit 52 measures an interval betweenedges of recording marks and stores the measured value in a memory inthe system control circuit 52 (S108).

Then, the system control circuit (a recording condition determinationmeans) 52 calculates the average of measured values of intervals betweenedges that have been stored in the memory (S109). The system controlcircuit 52 determines the difference between the interval calculated atS109 and an original interval between edges in the test signal (forexample, in the case of the test signals shown in FIGS. 11 to 14, thedifference between 15T and the time corresponding to the intervalcalculated) (S110: a comparison means). Then, an edge position of arecording pulse (for example, the leading edge of a recording pulse forrecording a 3T mark in examples as shown in FIGS. 11 to 14) isdetermined to be the position compensated for the above-mentioneddifference (S111). The edge compensation volume is set in the recordingpulse edge adjusting circuit 7 (S112).

As the last step, the polarity inversion control circuit 53 cancels theinhibition for polarity inversion that has been set at 101 (S113) sothat the switch in the select circuit 55 can be switched at random ineach sector, thus completing the test recording.

When information signals actually are recorded after the test recording,the switch in the select circuit 55 is switched at random in eachsector. Thus, the condition of the information signal is selected froman inverted condition and a non-inverted condition at random for eachsector. The inverted condition is obtained when the information signalis sent out to the recording signal generation circuit 6 while beinginverted by going through the polarity inverting circuit 54 from themodulation circuit 5. The non-inverted condition is obtained when theinformation signal is sent out to the recording signal generationcircuit 6 directly from the modulation circuit 5 without going throughthe polarity inverting circuit 54. As a result, even when similarinformation signals are recorded in the same sector repeatedly, thedamage to the specific portion of a recording film of the optical disk 1can be avoided.

As described above, in the present embodiment, by the control forinhibiting random polarity inversion in a recording data signal onlywhen the test recording is carried out, a leading edge and a rear edgeof each recording mark can be distinguished in determining edgepositions of recording marks, thus enabling information signals to berecorded precisely. In addition, when information signals actually arerecorded, the polarity of the recording data signal is controlled to beinverted at random in each sector or at each time overwriting is carriedout, thus obtaining an excellent effect in that the number of times theoptical disk can be rewritten can be increased.

In contrast to the above, at S101, the polarity inversion controlcircuit 53 may control the switching of the switch in the select circuit55 so that all the test signals sent out from the edge test signalgeneration circuit 4 are sent to the polarity inverting circuit 54 andthus their polarity is inverted. In short, what is required is that thepolarity of the recording data signal is constant at all timesthroughout a series of test recording.

In the present embodiment, the edge test signal generation circuit 4 wasprovided and the configuration and method for determining optimum edgepositions of recording pulses by the test recording were explained.However, as in the third embodiment, the power test signal generationcircuit (the second test signal generation means) 33 may be furtherprovided, and the configuration and method in which the system controlcircuit (a second recording condition determination means) 52 determinesrecording power also may be employed additionally. In this case, it ispreferred to control the select circuit to cancel the inhibition ofpolarity inversion in a process for determining recording power for thefollowing reason. Since there is a high possibility that the testrecording for determining recording power is carried out with a higherrecording power than that used in the test recording for determiningedge positions of recording pulses or in the normal recording ofinformation signals, polarity inversion suppresses the deterioration ofa recording film when recording is carried out on a test trackrepeatedly.

Moreover, when the configuration and method as described in the firstembodiment in which the recording start point shifting circuit 3 isprovided, the recording start point is shifted at random and a testsignal is recorded and reproduced in a plurality of sectors to determinethe optimum edge positions of recording pulses also are usedadditionally in the present embodiment, the test recording fordetermining edge positions of recording marks precisely without causingvariation can be carried out, which is more preferable.

In addition, when the configuration and method as described in thesecond embodiment in which the data pattern generation circuit 21 isprovided and a data pattern having substantially no correlation with thepattern of a test signal is recorded beforehand on a track on which thetest signal for determining edge positions of recording pulses is to berecorded also are used additionally, the test recording for determiningedge positions of recording marks precisely without causing variationcan be carried out, which is more preferable.

Sixth Embodiment

In a sixth embodiment of the present invention, a recording/reproducingapparatus with the configuration shown in FIG. 1 in the aforementionedfirst embodiment is used, but as the optical disk 1, one with a Z-CLVformat is used. The operation of the recording/reproducing apparatus inthe present embodiment will be explained using FIG. 1 and the flowchartshown in FIG. 10 as follows.

In test recording, first the optical head 9 seeks a track in thevicinity of the innermost circumference in any zone within a recordingregion on the optical disk 1 (S121) and the system control circuit 2sets the recording power in the laser drive circuit 8 to a predeterminedvalue (S122). Then, the edge test signal generation circuit 4 sends outa test signal to the recording signal generation circuit 6 as arecording data signal (S123). The recording signal generation circuit 6converts the recording data signal to recording pulses and the laserdrive circuit 8 modulates a current for driving a laser beam source (notshown in the figure) in the optical head 9, thus carrying out the testrecording on the sector (S124).

After recording the test signal, the optical head 9 reproduces the testsignal from the sector in which the test recording has been carried out(S125) and the reproduction signal processing circuit 11 equalizes andbinarizes a reproduction signal. Then, the edge timing detecting circuit12 slices the binarized signal and detects an inversion interval in thesignal (S126), thus measuring an interval between edges of recordingmarks. The measured value is stored in a memory (not shown in thefigure) in the system control circuit 2 (S127). Further, the systemcontrol circuit 2 calculates the average of intervals between edges frommeasured values that have been stored in the memory (S128).

The system control circuit 2 determines the difference between theinterval calculated at S128 and an original interval between edges inthe test signal (for example, in the case of the test signals shown inFIGS. 11 to 14, the difference between 15T and the time corresponding tothe interval calculated) (S129). Then, an edge position of a recordingpulse (for example, the leading edge of a recording pulse for recordinga 3T mark in examples as shown in FIGS. 11 to 14) is determined to bethe position compensated for the above-mentioned difference (S130). Theedge compensation volume is set in the recording pulse edge adjustingcircuit 7 (S131).

Next, a comparative experiment carried out for confirming the effect ofthe present embodiment will be explained as follows. In this experiment,instead of the measurement of a bit error rate, jitter in a reproductionsignal was measured by a time interval analyzer. The time intervalanalyzer was also used in detecting timings of edges in the reproductionsignal.

Table 1 shows a zone format of a substrate of an optical disk 1 used inthe experiment. This format is formed as a Z-CLV format with a constantrotation speed in each zone in which a recording region (i.e. the regionwhere information signals actually are recorded) located between aradius of 25.0 mm to 50 mm is divided into 10 zones. The clock cycle isconstant throughout the whole recording region. The present embodimentemploys a format in which the linear velocity in the innermostcircumference in each zone is the same. However, the linear velocity isnot always required to be the same in the innermost circumference ineach zone.

TABLE 1 Radius of Radius of Linear Velocity Linear Velocity Mark Lengthin Mark Length in Innermost Outermost Rotation in Innermost in OutermostChannel Innermost Outermost Circumference Circumference SpeedCircumference Circumference Clock Circumference Circumference Zone [mm][mm] [rpm] [m/s] [m/s] [ns] [μm] [μm] 0 25.00 27.50 3132 8.20 9.02 17.090.42 0.46 1 27.50 30.00 2847 8.20 8.95 17.09 0.42 0.46 2 30.00 32.502610 8.20 8.88 17.09 0.42 0.46 3 32.50 35.00 2409 8.20 8.83 17.09 0.420.45 4 35.00 37.50 2237 8.20 8.79 17.09 0.42 0.45 5 37.50 40.00 20888.20 8.75 17.09 0.42 0.45 6 40.00 42.50 1958 8.20 8.71 17.09 0.42 0.45 742.50 45.00 1842 8.20 8.68 17.09 0.42 0.45 8 45.00 47.50 1740 8.20 8.6617.09 0.42 0.44 9 47.50 50.00 1649 8.20 8.63 17.09 0.42 0.44

The substrate of the optical disk 1 used was made of polycarbonate resinand had a diameter of 120 mm and a thickness of 0.6 mm. In the resinsubstrate, phase pits of concave and convex shapes were preformatted asaddress information and recording tracks were formed in a sector area.The track pitch was 1.2 μm. On the substrate, a protective film, aphase-change recording film, a protective film, and a reflection filmwere formed by spattering, and then a protective substrate was bondedthereto.

In this case, ZnS—SiO₂ was used as the protective film, Te—Sb—Ge as thephase-change recording film, and Al as the reflection film. The opticaldisk 1 was rotated by a spindle motor 10 at the rotation speed describedin Table 1. A laser beam with a wavelength of 660 nm was focused by anobjective lens with a numerical aperture (NA) of 0.6, thus carrying outrecording and reproduction. The full width at half maximum of a spotsize was 0.62 μm.

The power of a laser beam in test recording was set to P_(p)=11 mW,P_(b)=5 mW, and P_(r)=1 mW. A modulation system of recording informationemployed herein was (8-16) pulse-width modulation that is used in DVD. Amark length of 3T, which is the shortest mark, was set to 0.42 μm.

Prior to the recording of information signals, test recording wascarried out on a track in the vicinity of the innermost circumference inZone 0 to determine edge positions of recording pulses. Thedetermination procedure followed the procedure shown in the flowchart inFIG. 2 in the first embodiment.

In all the nine combinations of lengths of marks to be recorded (a 3Tmark, a 4T mark, and a mark of at least 5T) and lengths of spacesdirectly before the respective marks (a 3T space, a 4T space, and aspace of at least 5T), respective leading ends of edge positions ofrecording pulses were determined. Similarly, respective rear ends ofedge positions of recording pulses were determined in all the ninecombinations of lengths of marks to be recorded (a 3T mark, a 4T mark,and a mark of at least 5T) and lengths of spaces directly behind therespective marks (a 3T space, a 4T space, and a space of at least 5T).The edge positions were adjusted with a precision of 0.5 ns.

In this case, an adjusted value for the edge positions in the 3T and 4Tmarks was different from that for the mark of at least 5T for thefollowing reason. Since recording pulse length is short in the 3T and 4Tmarks, their lengths tend to be short with respect to a spot size.Therefore, the edge positions of the 3T and 4T marks are required to bedifferent from those of the mark of at least 5T. The adjusted values foredge positions were changed in the 3T and 4T spaces and in the space ofat least 5T, since the influence of thermal interference between markscannot be ignored in the case of the 3T and 4T spaces.

Then, based on the edge positions of recording pulses determined in thetest recording, random information signals modulated by the (8-16)pulse-width modulation were overwritten and thus recorded ten times on atrack in the vicinity of the innermost circumference (i.e. at a radiusof 25.0 mm) and a track in the vicinity of the outermost circumferencein Zone 0, and then jitter in reproduction signals was measured.

Similarly in the above, test recording was carried out on a track in thevicinity of the outermost circumference (i.e. at a radius of 27.5 mm) inZone 0 to determine edge positions of recording pulses. Then, based onthe edge positions of recording pulses recorded in the test recording,random information signals modulated by the (8-16) pulse-widthmodulation were overwritten and thus recorded ten times on a track inthe vicinity of the innermost circumference and a track in the vicinityof the outermost circumference in Zone 0, and then jitter inreproduction signals was measured. The measurement results of jitter areshown in Table 2.

TABLE 2 Track for Test Recording Innermost Outermost Circumference inCircumference in Zone 0 Zone 0 Track for Recording Information SignalInnermost 9.3% 10.4% Circumference in Zone 0 Outermost 8.6% 8.5%Circumference in Zone 0

As shown in Table 2, it was found that the jitter in the randominformation signals was better in the vicinity of the outermostcircumference in the zone regardless of whether the test recording wascarried out on the track in the vicinity of the innermost circumferenceor on the track in the vicinity of the outermost circumference in thezone. The reason is that the recording linear density in the outermostcircumference in the zone is lower than that in the innermostcircumference. For instance, as shown in Table 1, the shortest mark inthe outermost circumference is 1.1 times longer than one in theinnermost circumference in Zone 0.

The jitter obtained when the test recording was carried out in theinnermost circumference in the zone and random information signals wererecorded in the outermost circumference was substantially the same asthat obtained when the test recording was carried out in the outermostcircumference in the zone and random information signals were recordedin the outermost circumference. On the other hand, the jitter obtainedwhen the test recording was carried out in the outermost circumferencein the zone and random information signals were recorded in theinnermost circumference increased about 1% compared to that obtainedwhen the test recording was carried out in the innermost circumferencein the zone and random information signals were recorded in theinnermost circumference.

The reason may be explained as follows. Since the recording lineardensity is low in the outermost circumference in the zone, the jittervalue varies a little corresponding to the shifts in edge positions ofrecording pulses when the test recording is carried out. Therefore, itcan be assumed that an adjustment error occurs easily in adjusting theedge positions by the test recording and the influence of the adjustmenterror appears as the increase in jitter value obtained when therecording is carried out in the innermost circumference.

As described above, in the present embodiment, a test signal is recordedwith the recording linear density substantially equal to that with whichinformation signals are recorded on the track in the innermostcircumference in each zone on the Z-CLV disk to determine edge positionsof recording pulses, thus obtaining an excellent effect in that goodjitter (or a good bit error rate) can be obtained throughout from theinnermost circumference to the outermost circumference in each zone andthus information signals can be recorded precisely.

In the present embodiment, the test recording was carried out in thevicinity of the innermost circumference within a zone in a recordingarea, i.e. the area where information signals are recorded, on theoptical disk. However, by providing an area in the vicinity of theinnermost circumference at least in one zone on an optical disk as atest recording area, the test recording may be carried out in the area.

As shown in Table 3, the same effect can be obtained when areas for testrecording are provided on the inner and outer sides with respect to arecording area on an optical disk and the recording linear density inthe areas is set to be substantially the same as that in the innermostcircumference in each zone.

TABLE 3 Radius of Radius of Linear Velocity Linear Velocity Mark Lengthin Mark Length in Innermost Outermost Rotation in Innermost in OutermostChannel Innermost Outermost Circumference Circumference SpeedCircumference Circumference Clock Circumference Circumference Zone [mm][mm] [rpm] [m/s] [m/s] [ns] [μm] [μm] Test Recording 24.90 25.00 31458.20 8.23 17.09 0.42 0.42 Area 0 25.00 27.50 3132 8.20 9.02 17.09 0.420.46 1 27.50 30.00 2847 8.20 8.95 17.09 0.42 0.46 2 30.00 32.50 26108.20 8.88 17.09 0.42 0.46 3 32.50 35.00 2409 8.20 8.83 17.09 0.42 0.45 435.00 37.50 2237 8.20 8.79 17.09 0.42 0.45 5 37.50 40.00 2088 8.20 8.7517.09 0.42 0.45 6 40.00 42.50 1958 8.20 8.71 17.09 0.42 0.45 7 42.5045.00 1842 8.20 8.68 17.09 0.42 0.45 8 45.00 47.50 1740 8.20 8.66 17.090.42 0.44 9 47.50 50.00 1649 8.20 8.63 17.09 0.42 0.44 Test Recording50.00 50.10 1566 8.20 8.22 17.09 0.42 0.42 Area

Further, in the present embodiment, the test recording for determiningthe edge positions of recording pulses was explained. However, in thecase of the test recording for determining recording power, thefollowing effect can be obtained. When the test recording is carried outwith the recording linear density substantially equal to that with whichinformation signals are recorded on a track in the innermostcircumference in each zone in a recording area, an optimum recordingpower can be set throughout from an inner circumference to an outercircumference in each zone and thus information signals can be recordedprecisely.

Moreover, when the configuration and method as described in the firstembodiment in which the recording start point shifting circuit 3 isprovided, the recording start point is shifted at random and a testsignal is recorded and reproduced in a plurality of sectors to determinethe optimum edge positions of recording pulses also are usedadditionally in the present embodiment, the test recording fordetermining edge positions of recording marks precisely without causingvariation can be carried out, which is more preferable.

In addition, when the configuration and method as described in thesecond embodiment in which the data pattern generation circuit 21 isprovided and a data pattern having substantially no correlation with thepattern of a test signal is recorded beforehand on a track on which thetest signal for determining edge positions of recording pulses is to berecorded also are used additionally, the test recording for determiningedge positions of recording marks precisely without causing variationcan be carried out, which is more preferable.

Further, when the configuration and method as described in the fifthembodiment in which a polarity inversion control circuit 53, a polarityinverting circuit 54, and a select circuit 55 are provided and randompolarity inversion of a recording data signal is inhibited only when thetest signal for determining edge positions of recording pulses isrecorded also are used additionally, the number of times the opticaldisk can be rewritten increases and information signals can be recordedprecisely, which is further preferable.

In the aforementioned first to sixth embodiments, the desirable timingsfor carrying out the test recording include at least the times inadjusting the recording/reproducing apparatus; on starting therecording/reproducing apparatus; after a lapse of a predetermined timefrom the starting; in exchanging the optical disk; when a bit error rateof the optical disk exceeds a predetermined value; and whenenvironmental temperature changes.

By carrying out test recording in adjusting recording/reproducingapparatuses, variable factors among the recording/reproducingapparatuses can be compensated. By carrying out test recording onstarting a recording/reproducing apparatus and after a lapse of apredetermined time from the starting, variable factors in therecording/reproducing apparatus itself can be compensated. By carryingout test recording in exchanging an optical disk, variable factorsbetween optical disks can be compensated. Similarly, by carrying outtest recording when a bit error rate of an optical disk exceeds apredetermined value, variable factors in the optical disk itself can becompensated. Further, by carrying out test recording when theenvironmental temperature changes, the variable factors caused by thetemperature dependency of a recording/reproducing apparatus and anoptical disk can be compensated.

The aforementioned first to sixth embodiments employed the configurationand method of recording a specific test signal for determining edgepositions of recording pulses and then measuring an interval betweenedges in a signal reproduced. However, the same effect can be obtainedin the configuration and method in which plural kinds of test signals(for example, plural kinds of random signals) with variable edgepositions are recorded, then a bit error rate (or jitter) is measured,and an edge position of a recording pulse set based on the test signalcausing the lowest bit error rate (or jitter) is determined as anoptimum value.

The aforementioned first to sixth embodiments employed the configurationand method in which the difference between an interval between edges ofrecording marks measured by recording a specific test signal and anoptimum interval between edges is compensated in the edge positionadjusting circuit to determine edge positions of recording pulses.However, the same effect can be obtained in the configuration and methodin which plural kinds of test signals in which edge positions ofrecording pulses are changed gradually are recorded, an interval betweenedges of recording marks are measured in each test signal, and then anedge position of a recording pulse in the test signal in which anoptimum interval between edges is obtained is set in the edge positionadjusting circuit as an optimum value.

Further, in the aforementioned first to sixth embodiments, an intervalbetween edges of recording marks was measured in the edge timingdetecting circuit and the system control circuit stored measuredintervals between edges and calculated the average thereof However,these processes may be carried out with an external measuring instrumentsuch as, for example, a time interval analyzer, outside therecording/reproducing apparatus.

In addition, in the aforementioned first to sixth embodiments, the testsignal generation circuit was provided for generating test signals.However, signals modulated by allowing the system control circuit togenerate specific information signals may be used as the test signals.In this case, it is not necessary to provide the test signal generationcircuit separately, thus reducing the size of the apparatus.Furthermore, those obtained by adding an error correction code to thetest signals or carrying out interleave processing also may be used. Thebit error rate may be measured after demodulation and error correction.

The number of layers, configuration, and materials of theabove-mentioned optical disk are not limited to those mentioned above.The above-mentioned method can be applied to any media, for example,using magnet-optical materials, dye materials, or the like as long asthe media have different optical characteristics in recording marks andin the regions without marks. However, in the case of optical disksusing a phase-change material as a recording film, optical absorption isdifferent between crystalline and amorphous states and thereforeparticularly a great effect can be obtained in the above-mentioned testrecording methods.

In addition, the aforementioned recording power, linear velocity,modulation method, recording density, length and position of each pulse,pattern of test signals, and the like are not limited to those used inthe embodiments. Needless to say, they can be set suitably according tothe recording conditions and media. Moreover, the measurement of a biterror rate may be replaced by the measurement of jitter and vice versa.

The embodiments described above are to be considered in all respects asillustrative for the purpose of making the technical contents of thepresent invention clear and the present invention is not to beinterpreted by limiting to such embodiments. The present invention canbe carried out by changing the embodiments variously within the spiritand the range described in the appended claims, and the presentinvention should be interpreted broadly.

What is claimed is:
 1. An optical information recording apparatus inwhich a rewritable optical information recording medium is used and,before recording an information signal on the optical informationrecording medium, test recording is carried out on the opticalinformation recording medium, the optical information recordingapparatus comprising: a test signal generation means that generates atest signal; a recording means that converts the test signal and theinformation signal to a recording data signal, drives a light sourcebased on the recording data signal, and records the test signal and theinformation signal on the optical information recording medium; a datapattern generation means that generates a data pattern havingsubstantially no correlation with the test signal; a reproducing meansthat reproduces signals from the optical information recording medium;and a recording condition determination means that allows the datapattern generation means to supply the data pattern to the recordingmeans to record the data pattern in an area for carrying out the testrecording on the optical information recording medium, then allows thetest signal generation means to supply the test signal to the recordingmeans to overwrite the test signal in the area, and determines a propervalue for edge positions of recording pulses in the recording datasignal based on a result obtained by reproducing the test signal fromthe area by the reproducing means.
 2. The optical information recordingapparatus according to claim 1, wherein the optical informationrecording apparatus is further provided with a recording start pointshifting means that shifts a recording start point at random in eachsector on the optical information recording medium to shift therecording start point at least of the test signal at random.
 3. Theoptical information recording apparatus according to claim 1, whereinthe data pattern is a random pattern.
 4. The optical informationrecording apparatus according to claim 1, wherein the test recording andrecording conditions are set at least at one timing selected from thetimes: in adjusting the optical information recording apparatus; onstarting the optical information recording apparatus; after a lapse of apredetermined time from the starting; in exchanging the opticalinformation recording medium; when a bit error rate of the opticalinformation recording medium exceeds a predetermined value; and whenenvironmental temperature of the optical information recording apparatuschanges.
 5. The optical information recording apparatus according toclaim 1, wherein a recording film of the optical information recordingmedium is formed of a phase-change material.
 6. An optical informationrecording method in which a rewritable optical information recordingmedium is used and, before recording an information signal on theoptical information recording medium, test recording is carried out onthe optical information recording medium, the optical informationrecording method comprising steps of: (a) generating a data patternhaving substantially no correlation with a test signal used for the testrecording; (b) converting the data pattern generated to a recording datasignal, driving a light source based on the recording data signal, andrecording the data pattern in an area for carrying out the testrecording on the optical information recording medium; (c) generatingthe test signal; (d) converting the test signal generated to a recordingdata signal, driving the light source based on the recording datasignal, and overwriting the test signal in the area on the opticalinformation recording medium; (e) reproducing the test signaloverwritten at the step (d) from the area on the optical informationrecording medium; and (f) determining a proper value for edge positionsof recording pulses in the recording data signal based on a resultobtained by reproducing the test signal.
 7. The optical informationrecording method according to claim 6, wherein the optical informationrecording method further comprises a step of shifting a recording startpoint at random in each sector on the optical information recordingmedium and in the step the recording start point at least of the testsignal is shifted at random.
 8. The optical information recording methodaccording to claim 6, wherein the data pattern is a random pattern. 9.The optical information recording method according to claim 6, wherein arecording film of the optical information recording medium is formed ofa phase-change material.
 10. An optical information recording apparatusthat records information on an optical information recording medium byan optical information recording method in which a rewritable opticalinformation recording medium is used and, before recording aninformation signal on the optical information recording medium, testrecording is carried out on the optical information recording medium,the optical information recording method comprising steps of: (a)generating a data pattern having substantially no correlation with atest signal used for the test recording; (b) converting the data patterngenerated to a recording data signal, driving a light source based onthe recording data signal, and recording the data pattern in an area forcarrying out the test recording on the optical information recordingmedium; (c) generating the test signal; (d) converting the test signalgenerated to a recording data signal, driving the light source based onthe recording data signal, and overwriting the test signal in the areaon the optical information recording medium; (e) reproducing the testsignal overwritten at the step (d) from the area on the opticalinformation recording medium; and (f) determining a proper value foredge positions of recording pulses in the recording data signal based ona result obtained by reproducing the test signal, wherein the testrecording and recording conditions are set at least at one timingselected from the times: in adjusting the recording/reproducingapparatus; on starting the recording/reproducing apparatus; after alapse of a predetermined time from the starting; in exchanging theoptical information recording medium; when a bit error rate of theoptical information recording medium exceeds a predetermined value; andwhen environmental temperature of the optical information recordingapparatus changes.